Z-M. Huang /Computers and Structures 80(2002)1177-1199 Table I Properties of E-glass 21 x K43 Gevetex and LY556/HT907/DY063 epoxy UD lamina Fiber Provided Predicted Provided Used Provided Used Eu(gPa) Ex(GPa 177 4.38 3.35 3.35 Gn(Gpa) 5.72 33.33 33 l.24 0.278 0.35 GY),(MPa)y (ar)2(MP (aY)3(MPa) 44.7 (OY)(MPa) (aY)s(MPa) (ar),(MPa)a GY)(mPa) (ET),(mPa)a Er),(MPa)a ET)(MPa) TTT 1140 2150 9089 55.7 (MPa) MPar 114 GS( (MPay 2.132 2.227 0.692 0.644 1087 2a12(% 7.638 x2(×10-O)26.4 9 58 20.478 (MPa) 62000 -6.863 l28 Fiber volume fraction: Vr =0.62; stress-free temperature: 120C; working temperature: 25C: bridging parameters used: B=0.45 and Assumed to be the same in both tension and compression Longitudinal compression d transverse tension Transverse compression. subsequent predictions Predicted thermal residual stress, from stress-free temperature to working temperature in the prediction for the whole response of the corre- hand, the in-plane shear stress-shear strain curves of the sponding laminate tems were provided [6]. These curves are used to retry UD laminae fabricated from all the four material sy strength and hardening modulus) measured using the plastic parameters of the respective matrix material a It is expected that the matrix plastic parameters(yield monolithic material specimens can be directly employed Compared with a transverse stress-strain response, the just as in the employment of the constituent thermo- in-plane shear stress curve generally displays more elastic properties. However, no detailed information distinct nonlinear behavior. It is noted that whenever about the matrix plasticity was given [6]. On the other possible the matrix notin the prediction for the whole response of the corre￾sponding laminate. It is expected that the matrix plastic parameters (yield strength and hardening modulus) measured using monolithic material specimens can be directly employed, just as in the employment of the constituent thermo￾elastic properties. However, no detailed information about the matrix plasticity was given [6]. On the other hand, the in-plane shear stress–shear strain curves of the UD laminae fabricated from all the four material sys￾tems were provided [6]. These curves are used to retrieve the plastic parameters of the respective matrix materials. Compared with a transverse stress–strain response, the in-plane shear stress–strain curve generally displays more distinct nonlinear behavior. It is noted that whenever possible the matrix plastic parameters should not be Table 1 Properties of E-glass 21  K43 Gevetex and LY556/HT907/DY063 epoxy UD lamina Properties Lamina Fiber Resin Provided Predicted Provided Used Provided Used E11 (GPa) 53.48 50.87 80 80 3.35 3.35 E22 (GPa) 17.7 14.38 80 80 3.35 3.35 G12 (Gpa) 5.83 5.72 33.33 33.33 1.24 1.24 m12 0.278 0.257 0.2 0.2 0.35 0.35 ðrYÞ1 (MPa)a – – – – – 31 .9 ðrYÞ2 (MPa)a – – – – – 38.4 ðrYÞ3 (MPa)a – – – – – 44.7 ðrYÞ4 (MPa)a – – – – – 49.9 ðrYÞ5 (MPa)a – – – – – 53.6 ðrYÞ6 (MPa)a – – – – – 56.1 ðrYÞ7 (MPa)a – – – – – 58.1 ðrYÞ8 (MPa)a – – – – – 60.0 ðETÞ1 (MPa)a – – – – – 1 566 ðETÞ2 (MPa)a – – – – – 1 337 ðETÞ3 (MPa)a – – – – – 944 ðETÞ4 (MPa)a – – – – – 584 ðETÞ5 (MPa)a – – – – – 338 ðETÞ6 (MPa)a – – – – – 245 ðETÞ7 (MPa)a – – – – – 1 97 rL u (MPa)b 1140 1140 2150 1804.1 80 56.5 rL u;c (MPa)c 570 570 1450 908.9 120 55.7 rT u (MPa)d 35 72 – – – – rT u;c (MPa)e 1 1 41 1 4– – – – rS u (MPa)f 72 84.8 –––– e11 (%)b 2.132 2.227 – 5 5.5434g e11;c (%)c 1.065 1.123 –––– e22 (%)d 0.197 0.692 –––– e22;c (%)e 0.644 1.087 –––– 2e12 (%)f 3.8 7.638 –––– a1ð106/C) 8.6 6.23 4.9 4.9 58 58 a2ð106/C) 26.4 20.62 4.9 4.9 58 58 r11 (MPa)h –0– 12.55g – 20.47g r22 (MPa)h –0– 6.86g – 11.2g r12 (MPa)h –0–0–0 Fiber volume fraction: Vf ¼ 0:62; stress-free temperature: 120 C; working temperature: 25 C; bridging parameters used: b ¼ 0:45 and a ¼ 0:35. a Assumed to be the same in both tension and compression. bLongitudinal tension. c Longitudinal compression. dTransverse tension. e Transverse compression. f In-plane shearing. g Not for use in subsequent predictions. h Predicted thermal residual stress, from stress-free temperature to working temperature. Z.-M. Huang / Computers andStructures 80 (2002) 1177–1199 1181