Search results for: total hip joint endoprosthesis

Authors: Harmonis Rante, Rudy Djamaluddin, Herman Parung, Victor Sampebulu

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Many research of FRP strengthening on beam-column joint have been done. They used FRP as a strengthening material but not as a connection method. This paper presents a result of experimental-study on connection method of precast beam-column using CFRP sheet to investigate the possibility of CFRP sheet to be a connecting material. Six specimens were prepared and tested to investigate the behavior of CFRP-s connection capacity. The performance of two-connection method is presented in this paper. Three specimens have been tested so far, they were specimen without belt, specimen using one belt and monolith specimen as a control specimen. Result indicated that FRP joint system without belt reached higher capacity than joint system using one belt, but both are lower than monolith joint. Capacity of joint system without belt is 90.6% and 62.5% for the joint system using one belt, respectively compared to the control specimen.

Keywords: belt, CFRP-s, connection method, strengthening

Procedia PDF Downloads 225

Authors: Pavel Boška, Jan Bomba, Tomáš Beránek, Jiří Procházka

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When using wood products bonded by polyvinyl acetate, glues such as windows are the most limiting element of degradation of the glued joint due to weather changes. In addition to moisture and high temperatures, the joint may damage the low temperature below freezing point, where dimensional changes in the material and distortion of the adhesive film occur. During the experiments, the joints were exposed to several degrees of sub-zero temperatures from 0 °C to -40 °C and then to compare how the decreasing temperature affects the strength of the joint. The experiment was performed on wood beech samples (Fagus sylvatica), bonded with PVAc with D3 resistance and the shear strength of bond was measured. The glued and treated samples were tested on a laboratory testing machine, recording the strength of the joint. The statistical results have given us information that the strength of the joint gradually decreases with decreasing temperature, but a noticeable and statistically significant change is achieved only at very low temperatures.

Keywords: adhesives, bond strength, low temperatures, polyvinyl acetate

Procedia PDF Downloads 325

Authors: Reza Aghayan

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This paper illustrates that numerically invariant joint signatures suffer biases in the resulting signatures. Next, we classify the arising biases as Bias Type 1 and Bias Type 2 and show how they can be removed.

Keywords: Euclidean and affine geometries, differential invariant signature curves, numerically invariant joint signatures, numerical analysis, numerical bias, curve analysis

Procedia PDF Downloads 562

Authors: Reza Kalantari, Ghazanfarah Hafeez

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The paper presents outcomes of the numerical research performed on standard and dovetail corner joints under lateral loads. An overview of the past research on log shear walls is also presented. To the authors’ best knowledge, currently, there are no specific design guidelines available in the code for the design of log shear walls, implying the need to investigate the performance of log shear walls. This research explores the performance of the log shear wall corner joint system of standard joint and dovetail types using numerical methods based on research available in the literature. A parametric study is performed to study the effect of gap size provided between two orthogonal logs and the presence of wood and steel dowels provided as joinery between log courses on the performance of such a structural system. The research outcomes are the force-displacement curves. 8% variability is seen in the reaction forces with the change of gap size for the case of the standard joint, while a variation of 10% is observed in the reaction forces for the dovetail joint system.

Keywords: dovetail joint, finite element modelling, log shear walls, standard joint

Procedia PDF Downloads 184

Authors: Young-Su Ryu, Su-Hyun Jung, Myoung-Jin Kim, Hyoung-Kyu Song

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In this paper, improved performance scheme for joint transmission is proposed in downlink (DL) coordinated multi-point(CoMP) in case of constraint transmission power. This scheme is that serving transmission point (TP) request a joint transmission to inter-TP and selects one pre-coding technique according to channel state information(CSI) from user equipment(UE). The simulation results show that the bit error rate(BER) and throughput performances of the proposed scheme provide high spectral efficiency and reliable data at the cell edge.

Keywords: CoMP, joint transmission, minimum mean square error, zero-forcing, zero-forcing dirty paper coding

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Authors: Nabeel Abdulkadhim Athab

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The purpose of this research is to conduct a comparative study according analysis of programmed to some of physical and mechanical variables for joint wrist injury. As it can be through this research to distinguish between the amount of variation in the work of the joint after sample underwent rehabilitation program to improve the effectiveness of the joint and naturally restore its effectiveness. Supposed researcher that there is statistically significant differences between the results of the tests pre and post the members research sample, as a result of submission the sample to the program of rehabilitation, which led to the development of muscle activity that are working on wrist joint and this is what led to note the differences between the results of the tests pre and post. The researcher used the descriptive method. The research sample included (6) of injured players in the wrist joint, as the average age (21.68) and standard deviation (1.13) either length average (178cm) and standard deviation (2.08). And the sample as evidenced homogeneous among themselves. And where the data were collected, introduced in program for statistical processing to get to the most important conclusions and recommendations and that the most important: 1-The commitment of the sample program the qualifying process variables studied in the search for the heterogeneity of study activity and effectiveness of wrist joint for injured players. 2-The analysis programmed a high accuracy in the measurement of the research variables, and which led to the possibility of discrimination into account differences in motor ability camel and injured in the wrist joint. To search recommendations including: 1-The use of computer systems in the scientific research for the possibility of obtaining accurate research results. 2-Programming exercises rehabilitation according to an expert system for possible use by patients without reference to the person processor.

Keywords: analysis of joint wrist injury, physical and mechanical variables, wrist joint, wrist injury

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Authors: Aizreena Azaman, Mai Ishibashi, Masanori Ishizawa, Shin-Ichiroh Yamamoto

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Sensory input plays an important role to human posture control system to initiate strategy in order to counterpart any unbalance condition and thus, prevent fall. In previous study, joint stiffness was observed able to describe certain issues regarding to movement performance. But, correlation between balance ability and joint stiffness is still remains unknown. In this study, joint stiffening strategy at ankle and hip were observed under different sensory manipulations and its correlation with conventional clinical test (Functional Reach Test) for balance ability was investigated. In order to create unstable condition, two different surface perturbations (tilt up-tilt (TT) down and forward-backward (FB)) at four different frequencies (0.2, 0.4, 0.6 and 0.8 Hz) were introduced. Furthermore, four different sensory manipulation conditions (include vision and vestibular system) were applied to the subject and they were asked to maintain their position as possible. The results suggested that joint stiffness were high during difficult balance situation. Less balance people generated high average joint stiffness compared to balance people. Besides, adaptation of posture control system under repetitive external perturbation also suggested less during sensory limited condition. Overall, analysis of joint stiffening response possible to predict unbalance situation faced by human.

Keywords: balance ability, joint stiffness, sensory, adaptation, dynamic

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Authors: Meltem Ramoglu, Ertugrul Safran, Hikmet Ucgun, Busra Kepenek Varol, Hulya Nilgun Gurses

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Down’s syndrome (DS) is a human genetic disorder caused by the presence of all or part of an extra chromosome 21. Many patients with DS have musculoskeletal problems that affect weak muscle tone (hypotonia) and ligament laxity. This leads to excessive joint hypermobility and decreased position sense (proprioception). Lack of proprioception may cause balance problems. The aim of our study was to investigate how does joint hypermobility affect balance in patients with DS. Our study conducted with 13 DS patients age between 18 to 40 years. Demographic data were recorded. Beighton Hypermobility Score (BHS) was used to evaluate joint hypermobility. Balance score of participants was evaluated with Berg Balance Scale (BBS). Mean age of our participants was 29,8±3,57 year. Average score of body mass index and BHS were; 33,23 ±3,78 kg/m2 and 7,61±1,04, respectively. Out of a maximum possible score of 56 on the Berg Balance Scale, scores of participants with DS ranged from 36–51, with a mean of 43±4,45. Significant correlation was found between BHS and BBS (r: -,966, p=0.00). All of our participants have 6/9 or higher grade from BHS. As a conclusion of our study; joint hypermobility may affect balance score in patients with DS. The results suggest that people with DS have worse balance scores which affected by hypermobility. Further studies need larger population for more reliable results.

Keywords: adults, balance, Down's syndrome, joint hypermobility

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Authors: Mohammad Alobaidy, David Nicoll, Tracey Wilkinson

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Background: Many patients suffer postoperative knee stability after total knee arthroplasty (joint replacement) involving posterior cruciate ligament (PCL) sacrificing or retaining, but is not clear whether the meniscofemoral ligaments (MFLs) are retained during these procedures; their function in terms of knee stability is not well established in the literature. Purpose: Macroscopic, detailed, morphometric investigation of the anterior and posterior MFLs of the knee joint was undertaken to assist understanding of knee stability after total knee arthroplasty and ligament reconstruction. Methods: Dissection of eighty Thiel embalmed knees from 19 male and 21 female cadavers was conducted, mean age 77 (range 47-99 years). The origin and insertion of the anterior and posterior MFLs were measured using high accuracy, calibrated, digital Vernier calipers at 0.01mm. Results: The means were: anterior meniscofemoral ligament (aMFL) length 28.4 ± 2.7mm; posterior meniscofemoral ligament (pMFL) length 29 ± 3.7mm; aMFL femoral width 6.4 ± 1.7mm, mid-distance ligament width 4 ± 1.1mm, meniscal ligament width 3.9 ± 1.2mm; pMFL femoral width 5.6 ± 1.5mm, mid-distance ligament width 4.1 ± 1.1mm, meniscal ligament width 4.1 ± 1.3mm. Some of the male measurements were larger than female, with significant differences in the length of the aMFL femoral length p<0.01 and pMFL femoral length p<0.007, and width of the pMFL mid-distance p<0.04. Conclusion: This study may help explore the role of the meniscofemoral ligaments in knee stability after total knee arthroplasty with a posterior cruciate ligament retaining prosthesis. Anatomical information for Thiel embalmed knees may aid orthopaedic surgeons in ligament reconstruction.

Keywords: anterior and posterior meniscofemoral ligaments, morphometric analysis, Thiel embalmed knees, knee arthroplasty

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Authors: Woo Young Jung, Min Ho Kwon, Bu Seog Ju

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A failure of the non-structural component can cause significant damages in critical facilities such as nuclear power plants and hospitals. Historically, it was reported that the damage from the leakage of sprinkler systems, resulted in the shutdown of hospitals for several weeks by the 1971 San Fernando and 1994 North Ridge earthquakes. In most cases, water leakages were observed at the cross joints, sprinkler heads, and T-joint connections in piping systems during and after the seismic events. Hence, the primary objective of this study was to understand the seismic performance of T-joint connections and to develop an analytical Finite Element (FE) model for the T-joint systems of 2-inch fire protection piping system in hospitals subjected to seismic ground motions. In order to evaluate the FE models of the piping systems using OpenSees, two types of materials were used: 1) Steel 02 materials and 2) Pinching 4 materials. Results of the current study revealed that the nonlinear moment-rotation FE models for the threaded T-joint reconciled well with the experimental results in both FE material models. However, the system-level fragility determined from multiple nonlinear time history analyses at the threaded T-joint was slightly different. The system-level fragility at the T-joint, determined by Pinching 4 material was more conservative than that of using Steel 02 material in the piping system.

Keywords: fragility, t-joint, piping, leakage, sprinkler

Procedia PDF Downloads 274

Authors: Bongsik Park, Jae Hyun Park, Jae-Yeol Cho

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Mixed structure, which is a kind of hybrid system, is incorporating steel beam and prestressed concrete beam. Hybrid bridge adopting mixed structure have some merits. Main span length can be made longer by using steel as main span material. In case of cable-stayed bridge having asymmetric span length, negative reaction at side span can be restrained without extra restraining devices by using weight difference between main span material and side span material. However angle of refraction might happen because of rigidity difference between materials and stress concentration also might happen because of abnormal loading transmission at joint in the hybrid bridge. Therefore the joint might be a weak point of the structural system and it needs to pay attention to design of the joint. However, design codes and standards about the joint in the hybrid-bridge have not been established so the joint designs in most of construction cases have been very conservative or followed previous design without extra verification. In this study parametric study using finite element analysis for optimal design of hybrid bridge joint is conducted. Before parametric study, finite element analysis was conducted based on previous experimental data and it is verified that analysis result approximated experimental data. Based on the finite element analysis results, parametric study was conducted. The parameters were selected as those have influences on joint behavior. Based on the parametric study results, optimal design of hybrid bridge joint has been determined.

Keywords: parametric study, optimal design, hybrid bridge, finite element analysis

Procedia PDF Downloads 390

Authors: Soonwon Kang, Jinwoong Choi, Sungnam Hong, Seung-Kyung Kye, Sun-Kyu Park

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The modular bridge is to be constructed by assembling standardized precast segments. This bridge is classified as a slab type and T-girder type. The T-girder bridge has transverse joint. However, it did not perform the verification on the transverse joint, but the slab type was done on the analytic study on the joint. Therefore, it is necessary for precast modular T-girder bridge that has a transverse joint to propose an appropriated model. In this study, specimens and analysis models compared integrated type with segmented type. Results of the integrated and segmented specimens, each of the deflection was 98.40mm and 74.66mm when the maximum load was 269.71kN and 248.29kN, in case of the modeling the specimens, each of the deflection was 84.04mm, 69.39mm when the maximum load was 269.71kN, 248.29kN, therefore, the precast T-girder modular bridges form the analytic model proposed appropriate.

Keywords: precast, T-girder modular bridge, finite element analysis, joint

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Authors: Shaher Bano, Samia Fida, Asif Israr

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The continuous development and exploitation of materials and designs have diverted the attention of the world towards the use of robust composite materials known as fiber-metal laminates in many high-performance applications. The hybrid structure of fiber metal laminates makes them a material of choice for various applications such as aircraft skin panels, fuselage floorings, door panels and other load bearing applications. The synergistic effect of properties of metals and fibers reinforced laminates are responsible for their high damage tolerance as the metal element provides better fatigue and impact properties, while high stiffness and better corrosion properties are inherited from the fiber reinforced matrix systems. They are mostly used as a layered structure in different joint configurations such as lap and but joints. The FML layers are usually bonded with each other using either mechanical fasteners or adhesive bonds. This research work is also focused on modification of an adhesive bonded joint as a single lap joint of carbon fibers based CARALL FML has been modified to increase interlaminar shear strength and avoid delamination. For this purpose different joint modification techniques such as the introduction of spews and shoulder to modify the bond shape and use of nanofillers such as carbon nano-tubes as a reinforcement in the adhesive materials, have been utilized to improve shear strength of lap joint of the adhesively bonded FML layers. Both the simulation and experimental results showed that lap joint with spews and shoulders configuration have better properties due to stress distribution over a large area at the corner of the joint. The introduction of carbon nanotubes has also shown a positive effect on shear stress and joint strength as they act as reinforcement in the adhesive bond material.

Keywords: adhesive joint, Carbon Reinforced Aluminium Laminate (CARALL), fiber metal laminates, spews

Procedia PDF Downloads 267

Authors: Azadeh Jafari, Mohammad Taghi Karimi, Azadeh Nadi

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Background: Scoliosis is the lateral curvature of the spine which may influence the abilities of the subjects during standing and walking. Most of the scoliotic subjects use orthosis to reduce the curve and to decrease the risk of curve progression. There was lack of information regarding the effects of orthosis on kinematic and joint contact force. Therefore, this research was done to highlight the effects of orthosis on the aforementioned parameters. Method: 5 scoliotic subjects were recruited in this study, with single curve less than 40 (females with age 13.2 ± 1.7). They were asked to walk with and without orthosis. The kinematic of the joints, force applied on the legs, moments transmitted through the joints and joint contact forces were evaluated in this study. Moreover, the lengths of muscles were determined by use of computer muscle control approach in OpenSim. Results: There was a significant difference between the second peak of vertical ground reaction force while walking with and without orthosis (p-value < 0.05). There was no difference between spatiotemporal gait parameters while walking with and without orthosis (P-value > 0.05). The mean values of joint contact forces (vertical component) increased by the use of orthosis, but the difference was not significant (p-value > 0.05). Conclusion: Although the kinematic of most of the body joints was not influenced by the use of orthosis, the joint contact force may be increased by orthosis. The increase in joint contact force may be due to the performance of orthosis which restricts the motions of pelvic and increases compensatory mechanism used by the subjects to decrease the side effects of the orthosis.

Keywords: scoliosis, joint contact force, kinetic, kinematic

Procedia PDF Downloads 180

Authors: Ezzeddin Anawa, Abdol-Ghane Olabi

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The dissimilar joint between aluminum /titanium alloys (Al 6082 and Ti G2) alloys were successfully achieved by CO2 laser welding with a single pass and without filler material using the overlap joint design. Laser welding parameters ranges combinations were experimentally determined using Taguchi approach with the objective of producing welded joint with acceptable welding profile and high quality of mechanical properties. In this study a joining of dissimilar Al 6082 / Ti G2 was result in three distinct regions fusion area (FA), heat-affected zone (HAZ), and the unaffected base metal (BM) in the weldment. These regions are studied in terms of its microstructural characteristics and microhardness which are directly affecting the welding quality. The weld metal was mainly composed of martensite alpha prime. In two different metals in the two different sides of joint HAZ, grain growth was detected. The microhardness of the joint distribution also has shown microhardness increasing in the HAZ of two base metals and a varying microhardness in fusion zone.

Keywords: microharness , microstructure, laser welding and dissimilar jointed materials.

Procedia PDF Downloads 349

Authors: Azadeh Rouhandeh, Chris Joslin, Zhen Qu, Yuu Ono

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The centre of rotation of the hip joint is needed for an accurate simulation of the joint performance in many applications such as pre-operative planning simulation, human gait analysis, and hip joint disorders. In human movement analysis, the hip joint center can be estimated using a functional method based on the relative motion of the femur to pelvis measured using reflective markers attached to the skin surface. The principal source of errors in estimation of hip joint centre location using functional methods is soft tissue artefacts due to the relative motion between the markers and bone. One of the main objectives in human movement analysis is the assessment of soft tissue artefact as the accuracy of functional methods depends upon it. Various studies have described the movement of soft tissue artefact invasively, such as intra-cortical pins, external fixators, percutaneous skeletal trackers, and Roentgen photogrammetry. The goal of this study is to present a non-invasive method to assess the displacements of the markers relative to the underlying bone using optical motion capture data and tissue thickness from ultrasound measurements during flexion, extension, and abduction (all with knee extended) of the hip joint. Results show that the artefact skin marker displacements are non-linear and larger in areas closer to the hip joint. Also marker displacements are dependent on the movement type and relatively larger in abduction movement. The quantification of soft tissue artefacts can be used as a basis for a correction procedure for hip joint kinematics.

Keywords: hip joint center, motion capture, soft tissue artefact, ultrasound depth measurement

Procedia PDF Downloads 254

Authors: Mukesh Roy, Basant Singh Sikarwar, Ravi Prakash, Priya Ranjan, Ayush Goyal

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More than 11% of people suffer from weakness in the bone resulting in inability in walking or climbing stairs or from limited upper body and limb immobility. This motivates a fresh bio-mimicking solution to the design of an exo-skeleton to support human movement in the case of partial or total immobility either due to congenital or genetic factors or due to some accident or due to geratological factors. A deeper insight and detailed understanding is required into the workings of the ball and socket joints. Our research is to mimic ball and socket joints to design snugly fitting exoskeletons. Our objective is to design an exoskeleton which is comfortable and the presence of which is not felt if not in use. Towards this goal, a parametric study is conducted to provide detailed design parameters to fabricate an exoskeleton. This work builds up on real data of the design of the exoskeleton, so that the designed exo-skeleton will be able to provide required strength and support to the subject.

Keywords: bio-mimicking, exoskeleton, ball joint, socket joint, artificial limb, patient rehabilitation, joints, human-machine interface, wearable robotics

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Authors: Ibrahim Abdel Gadir Malik, Dafalla Siddig Dafalla, Osama Abdelgadir El-Bushra

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Geological and engineering characteristics of intact rock and the discontinuity surfaces was used to describe and classify rock mass into zones based on mechanical and physical properties. Many conditions terms that affect the rock mas; such as Rock strength, Rock Quality Designation (RQD) value, joint spacing, and condition of joint, water condition with block size, joint roughness, separation, joint hardness, friction angle and weathering were used to classify the rock mass into: Good quality (class II) (RMR values range between 75% and 56%), Good to fair quality (class II to III) (RMR values range between 70% and 55%), Fair quality (class III) (RMR values range between 60% and 50%) and Fair to poor quality (Class III to IV) (RMR values, range between (50% and 35%).

Keywords: rock strength, RQD, joints, weathering

Procedia PDF Downloads 381

Authors: Loveneet Kaur

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Introduction: Osteoarthritis (OA) is one of the leading causes of disability, and the knee is the most commonly affected joint in the body. The last resort for treatment of knee OA is Total Knee Replacement (TKR) surgery. Despite numerous advances in prosthetic design, patients do not reach normal function after surgery. Current surgical decisions are made on 2D radiographs and patient interviews. Aims: The aim of this study was to compare knee kinematics pre and post-TKR surgery using computer-animated images of patient-specific models under everyday conditions. Methods: 7 subjects were recruited for the study. Subjects underwent 3D gait analysis during 4 everyday activities and medical imaging of the knee joint pre- and one-month post-surgery. A 3D model was created from each of the scans, and the kinematic gait analysis data was used to animate the images. Results: Improvements were seen in a range of motion in all 4 activities 1-year post-surgery. The preoperative 3D images provide detailed information on the anatomy of the osteoarthritic knee. The postoperative images demonstrate potential future problems associated with the implant. Although not accurate enough to be of clinical use, the animated data can provide valuable insight into what conditions cause damage to both the osteoarthritic and prosthetic knee joints. As the animated data does not require specialist training to view, the images can be utilized across the fields of health professionals and manufacturing in the assessment and treatment of patients pre and post-knee replacement surgery. Future improvements in the collection and processing of data may yield clinically useful data. Conclusion: Although not yet of clinical use, the potential application of 3D animations of the knee joint pre and post-surgery is widespread.

Keywords: Orthoporosis, Ortharthritis, knee replacement, TKR

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Authors: Sagar Pandit

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The present work focuses on the effect of various process parameters on the mechanical properties and microstructure of joints produced by continuous drive friction welding and linear friction welding. An attempt is made to investigate the feasibility of obtaining an acceptable weld joint between similar as well as dissimilar components and the microstructural changes have also been assessed once the good weld joints were considered (using Optical Microscopy and Scanning Electron Microscopy techniques). The impact of forging pressure in the microstructure of the weld joint has been studied and the variation in joint strength with varying forge pressure is analyzed. The weld joints were obtained two pair of dissimilar materials and one pair of similar materials, which are listed respectively as: Al-AA5083 & Cu-C101 (dissimilar), Aluminium alloy-3000 series & Mild Steel (dissimilar) and High Nitrogen Austenitic Stainless Steel pair (similar). Intermetallic phase formation was observed at the weld joints in the Al-Cu joint, which consequently harmed the properties of the joint (less tensile strength). It was also concluded that the increase in forging pressure led to both increment and decrement in the tensile strength of the joint depending on the similarity or dissimilarity of the components. The hardness was also observed to possess maximum as well as minimum values at the weld joint depending on the similarity or dissimilarity of workpieces. It was also suggested that a higher forging pressure is needed to obtain complete joining for the formation of the weld joint.

Keywords: forging pressure, friction welding, mechanical properties, microstructure

Procedia PDF Downloads 77

Authors: Bong-Su Sin, Jong-Kyu Kim, Se-Il Song, Kwon-Hee Lee

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An automobile ball joint is a pivoting element used to allow rotational motion between the parts of the steering and suspension system. And it plays a role in smooth transmission of steering movement, also reduction in impact from the road surface. A ball joint is under various repeated loadings that may cause cracks and abrasion. This damages lead to safety problems of a car, as well as reducing the comfort of the driver's ride, and raise questions about the ball joint procedure and the whole durability of the suspension system. Accordingly, it is necessary to ensure the high durability and reliability of a ball joint. The structural responses of stiffness and pull-out strength were then calculated to check if the design satisfies the related requirements. The analysis was sequentially performed, following the caulking process. In this process, the deformation and stress results obtained from the analysis were saved. Sequential analysis has a strong advantage, in that it can be analyzed by considering the deformed shape and residual stress. The pull-out strength means the required force to pull the ball stud out from the ball joint assembly. The low pull-out strength can deteriorate the structural stability and safety performances. In this study, two design variables and two noise factors were set up. Two design variables were the diameter of a stud and the angle of a socket. And two noise factors were defined as the uncertainties of Young's modulus and yield stress of a seat. The DOE comprises 81 cases using these conditions. Robust design of a ball joint was performed using the DOE. The pull-out strength was generated from the uncertainties in the design variables and the design parameters. The purpose of robust design is to find the design with target response and smallest variation.

Keywords: ball joint, pull-out strength, robust design, design of experiments

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Authors: Yuri Seu, Seong-Kyu Choi, Hyun Jin Park, Jin Seo Park, HongtaeKim, Mi-Sun Hur

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The aim of this study was to clarify the attachments of the distal oblique membrane (DOM) and distal oblique bundle (DOB) of the interosseous membrane of the forearm. The distal oblique membrane was investigated in the 21 specimens of 11 Korean cadavers. The muscles in the forearms were removed to observe the DOB. The DOB was found in 13 of 21 specimens (61.9 %). The DOB was attached to the distal radioulnar joint capsule and the septum between the tendons of the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) as well as the radius and ulna. In the cases that the DOB was absent, a part of the DOM extended to the distal radioulnar joint capsule and the septum between the tendons of the EDM and ECU, as well as the radius and ulna in all specimens (100%). The DOM, including the DOB, was arranged obliquely in the anteroposterior direction, whereas the intermediate part of the interosseous membrane was arranged in the same plane between the radius and ulna. The extension of the DOM and DOB to the wrist region may stabilize the distal radioulnar joint during supination and pronation. These data will be useful when performing reconstructive surgeries.

Keywords: distal oblique membrane, distal oblique bundle, distal radioulnar joint capsule, interosseous membrane

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Authors: T. N. Goh, M. Hashmi, O. Hussain

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Temporomandibular joint (TMJ) dysfunction (TMD) is a condition that may affect patients via restricted mouth opening, significant pain during normal functioning, and/or reproducible joint noise. TMD includes myofascial pain, TMJ functional derangements (internal derangement, dislocation), and TMJ degenerative/inflammatory joint disease. Internal derangement (ID) is the most common cause of TMD-related clicking and locking. These patients are managed in a stepwise approach, from patient education (homecare advice and analgesia), splint therapy, physiotherapy, botulinum toxin treatment, to arthrocentesis. Arthrotomy is offered when the aforementioned treatment options fail to alleviate symptoms and improve quality of life. The aim of this prospective study was to review the outcomes of jaw joint open surgery in TMD patients. Patients who presented from 2015-2022 at the Oral and Maxillofacial Surgery Department in the Doncaster NHS Foundation Trust, UK, with a Wilkes classification of III -V were included. These patients underwent either i) discopexy with bone-anchoring suture (9); ii) intrapositional temporalis flap (ITF) with bone-anchoring suture (3); iii) eminoplasty and discopexy with suturing to the capsule (3); iii) discectomy + ITF with bone-anchoring suture (1); iv) discoplasty + bone-anchoring suture (1); v) ITF (1). Maximum incisal opening (MIO) was assessed pre-operatively and at each follow-up. Pain score, determined via the visual analogue scale (VAS, with 0 being no pain and 10 being the worst pain), was also recorded. A total of 18 eligible patients were identified with a mean age of 45 (range 22 - 79), of which 16 were female. The patients were scored by Wilkes Classification as III (14), IV (1), or V (4). Twelve patients had anterior disc displacement without reduction (66%) and six had degenerative/arthritic changes (33%) to the TMJ. The open joint procedure resulted in an increase in MIO and reduction in pain VAS and for the majority of patients, across all Wilkes Classifications. Pre-procedural MIO was 22.9 ± 7.4 mm and VAS was 7.8 ± 1.5. At three months post-procedure there was an increase in MIO to 34.4 ± 10.4 mm (p < 0.01) and a decrease in the VAS to 1.5 ± 2.9 (p < 0.01). Three patients were lost to follow-up prior to six months. Six were discharged at six month review and five patients were discharged at 12 months review as they were asymptomatic with good mouth opening. Four patients are still attending for annual botulinum toxin treatment. Two patients (Wilkes III and V) subsequently underwent TMJ replacement (11%). One of these patients (Wilkes III) had improvement initially to MIO of 40 mm, but subsequently relapsed to less than 20 mm due to lack of compliance with jaw rehabilitation device post-operatively. Clinical improvements in 89% of patients within the study group were found, with a return to near normal MIO range and reduced pain score. Intraoperatively, the operator found bone-anchoring suture used for discopexy/discoplasty more secure than the soft tissue anchoring suturing technique.

Keywords: bone anchoring suture, open temporomandibular joint surgery, temporomandibular joint, temporomandibular joint dysfunction

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Authors: Seungwon Baek, Haeseok Jeong, Haehyun Lee, Woojin Park

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The main purpose of this study was to compare obese people to the non-obese in terms of joint kinematics in lower-limb body. The height of chairs was also considered as a design factor. Obese people had a difficulty in sit-to-stand (STS) tasks compared to the non-obese people. High chair heights can make STS task easy and it helps the obese to be more comfortable with STS task in particular. Subjects were instructed to wear inertial measurement unit (IMU) sensors. They perform STS task using chairs of different heights. Joint kinematics and subjective ratings of discomfort were measured. Knee angles of the obese group were greater than that of the non-obese group in normal type. No significant difference in joint kinematics was found in high chair. Interaction effect was found between obesity and height of chair. The results verified the previous research that had suggested a biomechanical model of STS movement. The results can be applied to occupational design for the obese.

Keywords: biomechanics, electromyography, joint kinematics, obesity, sitting, sit-to-stand

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Authors: Peter Kutis, Vladimir Littva

Abstract:

Nowadays, it is necessary to ensure that this reduction in costs is not at the expense of the quality of health care and future medical success. In general, physiotherapy for total hip joint arthroplasty is considered to be a routine matter that deals mainly with mobility training, increased muscular strength, and basic day-to-day activities such as bed-to-chair transition, standing, and walking. Within the KEGA project no. 003KU-4-2021, we decided to investigate preoperative physiotherapy care in Slovakia and Austria in total hip arthroplasty patients to shortened overall recovery. Research Sample and Methods: The sample comprised 498 respondents –patients who were indicated to total hip arthroplasty on the territory of Slovakia and Austria. There were 130 women in Slovakia and 135 women in Austria. The numbers of men were 120 in Slovakia and 113 men in Austria. The age of respondents was between 40 and 85 years of age. As a method of our research, we chose a non-standardized questionnaire, which consisted of three parts. The first part for the initial examination of the patient contained the identification of the patient according to the assigned number and subsequently 19 questions conditioned by the physical examination and evaluation of the patients. The second part of our questionnaire was completed after the patient's hospitalization and contained 10 questions that were conditioned by the patient's examination. The last third part for the overall assessment of the patient's state of health consisted of 12 questions conditioned by the patient's examination. This part was performed at the last meeting with the patient at the end of the treatment. All data were statistically processed by SPSS 25. Results: All data were evaluated at a significance level of p = 0.05. From the comparison of patients who underwent preoperative preparation, we can clearly state that the total duration of treatment is significantly shorter. A t-test of two mean values with uneven variance was used to verify the validity of the assumption. The total duration of treatment in patients with preoperative preparation was on average 92,635 days and without preoperative preparation was on average 135,884 days (t-Stat = 44,52784, t Critical one-tail = 1,648187415, t Critical two-tail = 1,965157). Conclusion: The results obtained during the research show the importance of adequate preoperative physiotherapeutic preparation of the patient. The results of total hip joint arthroplasty studies showed a significant reduction in a hospital stay as well as shortened total treatment time.

Keywords: THA, physiotherapy, recovery, preoperative physiotherapy care

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Authors: Jeron Maheswaran, Sudath C. Siriwardane

Abstract:

In fatigue analysis, the structural detail of tubular joint has taken great attention among engineers. The DNV-RP-C203 is covering this topic quite well for simple and clear joint cases. For complex joint and geometry, where joint classification isn’t available and limitation on validity range of non-dimensional geometric parameters, the challenges become a fact among engineers. The classification of joint is important to carry out through the fatigue analysis. These joint configurations are identified by the connectivity and the load distribution of tubular joints. To overcome these problems to some extent, this paper compare the fatigue life of tubular joints in offshore jacket according to the stress concentration factors (SCF) in DNV-RP-C203 and finite element method employed Abaqus/CAE. The paper presents the geometric details, material properties and considered load history of the jacket structure. Describe the global structural analysis and identification of critical tubular joints for fatigue life estimation. Hence fatigue life is determined based on the guidelines provided by design codes. Fatigue analysis of tubular joints is conducted using finite element employed Abaqus/CAE [4] as next major step. Finally, obtained SCFs and fatigue lives are compared and their significances are discussed.

Keywords: fatigue life, stress-concentration factor, finite element analysis, offshore jacket structure

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Authors: A. Sharma, S. S. Sandhu, A. Shahi, A. Kumar

Abstract:

The aim of present investigation was to carry out Finite element modeling of distortion in the case of butt weld. 12mm thick AISI 304L plates were butt welded using three different combinations of groove design namely Double U, Double V and Composite. A full simulation of shielded metal arc welding (SMAW) of nonlinear heat transfer is carried out. Aspects like, temperature-dependent thermal properties of AISI stainless steel above liquid phase, the effect of thermal boundary conditions, were included in the model. Since welding heat dissipation characteristics changed due to variable groove design significant changes in the microhardness tensile strength and impact toughness of the joints were observed. The cumulative distortion was found to be least in double V joint followed by the Composite and Double U-joints. All the joints have joint efficiency more than 100%. CVN value of the Double V-groove weld metal was highest. The experimental results and the FEM results were compared and reveal a very good correlation for distortion and weld groove design for a multipass joint with a standard analogy of 83%.

Keywords: AISI 304 L, Butt joint, distortion, FEM, groove design, SMAW

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Authors: Nina Robson, Kenneth John Faller II, Vishalkumar Ahir, Mustafa Mhawesh, Reza Langari

Abstract:

This paper describes the development of a model of an impaired human arm performing a reaching motion, which will be used to predict hand path trajectories for people with reduced arm joint mobility. Assuming that the arm was in contact with a surface during the entire movement, the contact conditions at the initial and final task locations were determined and used to generate the entire trajectory. The model was validated by comparing it to experimental data, which simulated an arm joint impairment by physically constraining the joint motion with a brace. Future research will include using the model in the development of physical training protocols that avoid early recruitment of “healthy” Degrees-Of-Freedom (DOF) for reaching motions, thus facilitating an Active Range-Of-Motion Recovery (AROM) for a particular impaired joint.

Keywords: higher order kinematic specifications, human motor coordination, impaired movement, kinematic synthesis

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Authors: Xinyuan Y. Song, Kai Kang

Abstract:

Joint models for analyzing longitudinal and survival data are widely used to investigate the relationship between a failure time process and time-variant predictors. A common assumption in conventional joint models in the survival analysis literature is that all predictors are observable. However, this assumption may not always be supported because unobservable traits, namely, latent variables, which are indirectly observable and should be measured through multiple observed variables, are commonly encountered in the medical, behavioral, and financial research settings. In this study, a joint modeling approach to deal with this feature is proposed. The proposed model comprises three parts. The first part is a dynamic factor analysis model for characterizing latent variables through multiple observed indicators over time. The second part is a random coefficient trajectory model for describing the individual trajectories of latent variables. The third part is a proportional hazard model for examining the effects of time-invariant predictors and the longitudinal trajectories of time-variant latent risk factors on hazards of interest. A Bayesian approach coupled with a Markov chain Monte Carlo algorithm to perform statistical inference. An application of the proposed joint model to a study on the Alzheimer's disease neuroimaging Initiative is presented.

Keywords: Bayesian analysis, joint model, longitudinal data, time-to-event data

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Authors: Reza Aghayan

Abstract:

Numerically invariant signatures were introduced as a new paradigm of the invariant recognition for visual objects modulo a certain group of transformations. This paper shows that the current formulation suffers from noise and indeterminacy in the resulting joint group-signatures and applies the n-difference technique and the m-mean signature method to minimize their effects. In our experimental results of applying the proposed numerical scheme to generate joint group-invariant signatures, the sensitivity of some parameters such as regularity and mesh resolution used in the algorithm will also be examined. Finally, several interesting observations are made.

Keywords: Euclidean and affine geometry, differential invariant G-signature curves, numerically invariant joint G-signatures, object recognition, noise, indeterminacy

Procedia PDF Downloads 367