Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32019
Simulation of the Visco-Elasto-Plastic Deformation Behaviour of Short Glass Fibre Reinforced Polyphthalamides

Authors: V. Keim, J. Spachtholz, J. Hammer


The importance of fibre reinforced plastics continually increases due to the excellent mechanical properties, low material and manufacturing costs combined with significant weight reduction. Today, components are usually designed and calculated numerically by using finite element methods (FEM) to avoid expensive laboratory tests. These programs are based on material models including material specific deformation characteristics. In this research project, material models for short glass fibre reinforced plastics are presented to simulate the visco-elasto-plastic deformation behaviour. Prior to modelling specimens of the material EMS Grivory HTV-5H1, consisting of a Polyphthalamide matrix reinforced by 50wt.-% of short glass fibres, are characterized experimentally in terms of the highly time dependent deformation behaviour of the matrix material. To minimize the experimental effort, the cyclic deformation behaviour under tensile and compressive loading (R = −1) is characterized by isothermal complex low cycle fatigue (CLCF) tests. Combining cycles under two strain amplitudes and strain rates within three orders of magnitude and relaxation intervals into one experiment the visco-elastic deformation is characterized. To identify visco-plastic deformation monotonous tensile tests either displacement controlled or strain controlled (CERT) are compared. All relevant modelling parameters for this complex superposition of simultaneously varying mechanical loadings are quantified by these experiments. Subsequently, two different material models are compared with respect to their accuracy describing the visco-elasto-plastic deformation behaviour. First, based on Chaboche an extended 12 parameter model (EVP-KV2) is used to model cyclic visco-elasto-plasticity at two time scales. The parameters of the model including a total separation of elastic and plastic deformation are obtained by computational optimization using an evolutionary algorithm based on a fitness function called genetic algorithm. Second, the 12 parameter visco-elasto-plastic material model by Launay is used. In detail, the model contains a different type of a flow function based on the definition of the visco-plastic deformation as a part of the overall deformation. The accuracy of the models is verified by corresponding experimental LCF testing.

Keywords: Complex low cycle fatigue, material modelling, short glass fibre reinforced polyphthalamides, visco-elasto-plastic deformation.

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1188


[1] C. A. Harper, Handbook of Plastic Processes, 1st ed. John Wiley & Sons, 2006.
[2] T. Jeltsch, “Metal replacement - To the limits of the possible,” Kunststoffe international, pp. 88–90, Aug. 2007.
[3] Y. R´emond, “Constitutive modelling of viscoelastic unloading of short glass fibre-reinforced polyethylene,” Composites Science and Technology, vol. 65, no. 3–4, pp. 421–428, 2005.
[4] L. Lemaitre and J. Chaboche, Mechanics of solid materials. Chambridge University Press, 1990.
[5] A. Launay, Y. Marco, M. H. Maitournam, I. Raoult, and F. Szmytka, “Cyclic behavior of short glass fiber reinforced polyamide for fatigue life prediction of automotive components,” Procedia Engineering, vol. 2, no. 1, pp. 901–910, 2010.
[6] A. Launay, M. H. Maitournam, Y. Marco, I. Raoult, and F. Szmytka, “Cyclic behaviour of short glass fibre reinforced polyamide: Experimental study and constitutive equations,” International Journal of Plasticity, vol. 27, no. 8, pp. 1267–1293, 2011.
[7] S. Mortazavian and A. Fatemi, “Fatigue behavior and modeling of short fiber reinforced polymer composites: A literature review,” International Journal of Fatigue, vol. 70, pp. 297–321, 2015.
[8] C. Schweizer, “Physikalisch basierte Modelle f¨ur Erm¨udungsrisswachstum und Anrisslebensdauer unter thermischen und mechanischen Belastungen,” Ph.D. dissertation, KIT, Kalsruhe, 2013.
[9] T. Seifert, M. Borsutzki, and S. Geisler, “Ein komplexes LCF-Versuchsprogramm zur schnellen und g¨unstigen Werkstoffparameteridentifizierung,” Fortschritte der Kennwertermittlung in Forschung und Praxis, 2006.
[10] T. Seifert, C. Schweizer, M. Schlesinger, M. M¨oser, and M. Eibl, “Thermomechanical fatigue of 1.4849 cast steel – experiments and life prediction using a fracture mechanics approach,” International Journal of Materials Research, vol. 101, no. 8, pp. 942–950, 2010.
[11] T. Seifert, “Simulation von Hochtemperaturbauteilen mittels FEM,” Freiburg, May 2012.
[12] J. Brunbauer, A. M¨osenbacher, C. Guster, and G. Pinter, “Fundamental influences on quasistatic and cyclic material behavior of short glass fiber reinforced polyamide illustrated on microscopic scale,” Journal of Applied Polymer Science, vol. 131, no. 19, Oct. 2014.
[13] S. Mortazavian and A. Fatemi, “Effects of fiber orientation and anisotropy on tensile strength and elastic modulus of short fiber reinforced polymer composites,” Composites Part B: Engineering, vol. 72, pp. 116–129, 2015.
[14] S. G. Advani and C. L. T. Iii, “The Use of Tensors to Describe and Predict Fiber Orientation in Short Fiber Composites,” Journal of Rheology (1978-present), vol. 31, no. 8, pp. 751–784, Nov. 1987.
[15] G. Ayoub, F. Za¨ıri, M. Na¨ıt-Abdelaziz, and J. M. Gloaguen, “Modelling large deformation behaviour under loading–unloading of semicrystalline polymers: Application to a high density polyethylene,” International Journal of Plasticity, vol. 26, no. 3, pp. 329–347, 2010.
[16] J.-L. Chaboche, “Thermodynamic formulation of constitutive equations and application to the viscoplasticity and viscoelasticity of metals and polymers,” International Journal of Solids and Structures, vol. 34, no. 18, pp. 2239–2254, 1997.
[17] A. Drozdov, A. Al-Mulla, and R. Gupta, “The viscoelastic and viscoplastic behavior of polymer composites: polycarbonate reinforced with short glass fibers,” Computational Materials Science, vol. 28, no. 1, pp. 16–30, 2003.
[18] A. D. Drozdov, A. Al-Mulla, and R. K. Gupta, “Finite viscoplasticity of polycarbonate reinforced with short glass fibers,” Mechanics of Materials, vol. 37, no. 4, pp. 473–491, 2005.
[19] J.-L. Chaboche and F. Gallerneau, “An overview of the damage approach of durability modelling at elevated temperature,” Fatigue & Fracture of Engineering Materials & Structures, vol. 24, no. 6, pp. 405–418, Jun. 2001.
[20] F. Dunne and N. Petrinic, Introduction to computational plasticity. Oxford: Oxford University Press, 2005.
[21] J. C. Simo and T. J. R. Hughes, Computational Inelasticity, 7th ed. Stanford: Springer Berlin, Heidelberg, 2000.
[22] F. Wilhelm, J. Spachtholz, M. Wagner, C. Kliemt, and J. Hammer, “Simulation of the Viscoplastic Material Behaviour of Cast Aluminium Alloys due to Thermal-Mechanical Loading,” Journal of Materials Science and Engineering. A, vol. 4, no. 1A, 2014.
[23] K. Noda, A. Takahara, and T. Kajiyama, “Fatigue failure mechanisms of short glass-fiber reinforced nylon 66 based on nonlinear dynamic viscoelastic measurement,” Polymer, vol. 42, no. 13, pp. 5803–5811, 2001.
[24] P. Germain, Q. S. Nguyen, and P. Suquet, “Continuum Thermodynamics,” Journal of Applied Mechanics, vol. 105, pp. 1010–1021, Dec. 1983.
[25] S. N. Sivanandam and S. N. Deepa, Introduction in genetic algorithms. Springer Berlin Heidelberg, 2008.
[26] X. Yu, Introduction to Evolutionary Algorithms. Springer London, 2010.
[27] K. Kraßnitzer, L¨osung des Traveling-Salesmans-Problems mittels eines genetischen Algorithmus auf einem HPC-Cluster, 1st ed. Grin Verlag, 2013.
[28] A. J. Chipperfield, P. J. Fleming, and C. M. Fonseca, “Genetic Algorithm Tools for Control Systems Engineering,” ResearchGate, vol. 23, no. 3, Jan. 1994.
[29] E. A. Eiben and J. Smith, Introduction to evolutionary computing, 1st ed. Springer, 2003.
[30] B. Kost, Optimierung mit Evolutionsstrategien, 1st ed. Hamburg: Harri Deutsch, 2003.
[31] P. Natterer, Philisophie der Biologie, 1st ed. Books on Demand, 2010.