The Influence of the Sample Size of Bias Extension Tests on the Results of Forming Simulations of Fiber-Reinforced Thermoplastics

Abstract:

This work presents sensitivity analyzes of the influence of deviations in the shear stress vs. shear angle curves of bias extension tests of fiber-reinforced thermoplastics on the results of forming simulations. The investigations are carried out on the basis of a double dome benchmark geometry from the Ford Motor Company. Its experimental results of shear angle values and wrinkling are compared to the simulation results. The initial values for sensitivity analyzes are the shear stress-shear angle curves determined within further preliminary investigations on the basis of different sample sizes and cutting directions. Then these are gradually scaled. Finally, it will be discussed which deviations in the shear stress-shear angle curve are permissible in order to achieve a maximum deviation of 20% between simulation results and the real part. This is assumed to be the target value for this study.

• Periodical: Key Engineering Materials (Volume 926)
• Pages: 1234-1239
• DOI: https://doi.org/10.4028/p-519mb6
• Online since: July 2022
• Authors: Jasmin Graef*, Bernd Engel
• Keywords: Bias Extension Test, Fiber Reinforced Thermoplastics, Forming Simulation

References

[1] D. Dörr, T. Joppich, F. Schirmaier, T. Mosthaf, L. Kärger, F. Henning, Sensitivity of material properties on wrinkling behavior and fiber reorientation of thermoplastic UD-Tape laminates during forming analyzed by Finite Element forming simulation, ECCM 17 - 17th European Conference on Composite Materials. Munich, Germany, (2016).

DOI: 10.1063/1.4963567

[2] P. Boisse, N. Hamila, E. Guzman-Maldonado, A. Madeo, G. Hivet, F. Dell´Isola, The bias-extension test for the analysis of in-plane shear properties of textile composite reinforcements and prepregs: a review, International Journal of Material Forming (10(4)), p.473–492, (2017).

DOI: 10.1007/s12289-016-1294-7

[3] J. Graef, B. Engel, Challenges of shear characterization in the bias extension test of fibre reinforced thermoplastics, SAMPE Europe Conference 2021 Baden/Zürich – Switzerland, (2021).

[4] J. Graef, B. Weiß, B. Engel, Measurement of fiber wrinkles and shear angles of Double Dome forming parts, ESAFORM 2021, 24th International Conference on Material Forming, Liège, (2021).

DOI: 10.25518/esaform21.3756

[5] B. Engel, J. Graef, Sensitivity Study of Material Input Data on FE Forming Results for Wrinkling and Shearing of Fiber Reinforced Thermoplastic Parts. In: Key Engineering Materials (Vol. 809), p.500–505, (2019).

DOI: 10.4028/www.scientific.net/kem.809.500

[6] B. Engel, J. Graef, Different material models for intra-ply shear and double-dome FE forming analysis, JEC COMPOSITES MAGAZINE (No 100), (2015).

[7] B. Engel, J. Graef, FE analysis of the influence of fiber orientation to shearing and wrinkling of fiber reinforced thermoplastic parts, Key Engineering Materials, Vol. 742, pp.732-739, (2017).

DOI: 10.4028/www.scientific.net/kem.742.732

[8] M. Nishi, T. Hirashima, T. Kurasiki, Textile composite reinforcement forming analysis considering out-of-plane bending stiffness and tension dependent in-plane shear behavior. In: 16th European Conference on Composite Materials- ECCM, Seville, Spain, (2014).

[9] B. Engel, J. Graef, Study of the bending stiffness of fibre-reinforced thermoplastics at forming temperature, JEC COMPOSITES MAGAZINE (102), p.38–41, (2016).

[10] DIN German institute for standardization, DIN 53362:2003-10. Testing of plastics films and textile fabrics (excluding nonwovens), coated or not coated fabrics - Determination of stiffness in bending - Method according to Cantilever, Berlin: Beuth Verlag, (2003).

[11] J. Cao, R. Akkerman, P. Boisse, J. Chen, et al., Characterization of mechanical behavior of woven fabrics: experimental methods and benchmark results, Compos Part A 39:1037–1053, (2008).

[12] W. Lee, J. Padvoiskis, J. Cao, E. de Luycker, P. Boisse, F. Morestin, Bias-extension of woven composie fabrics. In: Int J Mater Form (Suppl. 1), p.895–898, (2008).

DOI: 10.1007/s12289-008-0240-8

[13] G. Hivet, A. V. Duong, A contribution to the analysis of the intrinsic shear behavior of fabrics. In: Journal of Composite Materials 45 (6), p.695–716, (2011).

DOI: 10.1177/0021998310382315

[14] K. Friedrich, M. Hou, J. Krebs, Thermoforming of Continuous Fibre/Thermosplastic Composite Sheets. Editors: D. Bhattacharyya, Composite materials series, Elsevier, Volume 11, p.92–162, (1997).

DOI: 10.1016/s0927-0108(97)80006-9