scholarly journals Numerical Simulation Study on Strain Rate Effect of Fiber Reinforced Composites

2020 ◽  
Author(s):  
Hui Ye ◽  
Chang Liu ◽  
Yanrong Zhu

Abstract In order to study the effect of strain rate effect on the simulation precision of fiber reinforced composites, the dynamic enhancement factor (DIF) was introduced to modify the modulus and strength of the composite, and the modified Hashin failure criterion was used to establish a three-dimensional progressive damage constitutive model of composite materials which could consider the strain rate effect. The model is embedded into the Abaqus software by VUMAT subroutine, and the simulation of the projectile penetrating the fiberglass reinforced composite laminates is carried out. The simulation results are compared with the experimental results and the constitutive model simulation results without considering the strain rate effect. The results show that the constitutive model with strain rate established in this paper can accurately simulate the process of projectile penetrating the laminates. Compared with the simulation results without strain rate, the accuracy is increased in the model with strain rate, respectively by 14.1% at the penetration speed of 1.8 m/s and by 22.7% at 3 m/s. The errors, between the simulation results of without strain rate and that of the experiments, are increased with the increase of penetration speed, and increase from 28.7% of 1.8 m/s to 36.9% of 3 m/s. The simulation error of constitutive model with strain rate is relatively stable.

2006 ◽  
Vol 532-533 ◽  
pp. 973-976
Author(s):  
Lin Wang ◽  
Tai Chiu Lee ◽  
Luen Chow Chan

In this paper, the effect of strain rate has been considered in the simulation of forming process with a simple form combined into the material law. Quite a few researchers have proposed various hardening laws and strain rate functions to describe the material tensile curve. In this study, the strain rate model Cowper-Symonds is used with anisotropic elasto-plastic material law in the simulation process. The strain path evolution of certain elements, when the strain rate is considered and not, is compared. Two sheet materials, Cold-reduced Carbon Steel (SPCC) JIS G3141 and Aluminum alloy 6112 are used in this study. Two yield criteria, Hill 48 and Hill 90, are applied respectively to improve the accuracy of simulation result. They show different performance when strain rate effect is considered. Strain path of the elements in the fracture risk area of SPCC (JIS G3141) varies much when the strain rate material law is used. There is only little difference of the strain distribution of Al 6112 when the strain rate effect is included and excluded in the material law. The simulation results of material SPCC under two conditions indicate that the strain rate should be considered if the material is the rate-sensitive material, which provides more accurate simulation results.


2021 ◽  
Vol 36 (2) ◽  
pp. 213-218
Author(s):  
M. D. D. Boudiaf ◽  
L. Hemmouche ◽  
M. A. Louar ◽  
A. May ◽  
N. Mesrati

Abstract In this study, the strain rate sensitivity of a discontinuous short fiber reinforced composite and the strain rate effect on the damage evolution are investigated. The studied material is a polymeric composite with a polyamide 6.6 matrix reinforced with oriented randomly short glass fibers at a 50% weigh ratio (PA6.6GF50). Tensile tests at low and high strain rate are conducted. In addition, interrupted tensile tests are carried out to quantify the damage at specific stress levels and strain rates. To perform the interrupted tensile tests, an intermediate fixture is realized via double notched mechanical fuses with different widths designed to break at suitable stress levels. The damage is estimated by the fraction of debonded fibers and matrix fractures. Based on the experimental observations, it is concluded that the ultimate stress and strain, and the damage threshold are mainly governed by the strain rate. Furthermore, it is established that the considered composite has a non-linear dynamic behavior with a viscous damage nature.


2014 ◽  
Vol 609-610 ◽  
pp. 849-855
Author(s):  
Wen Rui Ma ◽  
Guang He

Under launch impact load, LIGA nickel that manufacturing MEMS fuze safety and arming (S&A) device will have obvious strain rate effect. By using finite element analysis software ANSYS/LS-DYNA, simulation models of a small-caliber ammunition MEMS fuze setback S&A device with strain rate effect and without strain rate effect were respectively established. The results of the two simulation modules were quite different. Comparisons between experimental results and simulation results show that simulation results considering strain rate effect agree well with experimental results, which proves strain rate effect should not be ignored in the simulation of MEMS S&A device.


2009 ◽  
Vol 79-82 ◽  
pp. 199-202
Author(s):  
Xin Yan Wu ◽  
Fu Ling Guan ◽  
Bin Chen ◽  
You Wei Wang

In this paper, microstructure and mechanical properties of the chafer cuticle were investigated. The microstructures of the chafer cuticle were first observed with a SEM. It showed that the cuticle is a kind of chitin-fiber-reinforced biocomposite with protein matrix. There are some holes existing in the chafer cuticle and the fibers around hole are continuous. Based on the observed results of the SEM, the analyses of 3D models on the simple composite elements with fiber-round hole were conducted. The result showed the microstructures of composite laminates with fiber-round holes can decrease the stress concentration and well transfer the stress. So it can improve the strength and toughness of the composite laminates included holes. These conclusions may present a bio-inspired approach for design and development of advanced man-made fiber-reinforced composites.


2008 ◽  
Vol 56 ◽  
pp. 84-91
Author(s):  
Tadashige Ikeda

A simple yet accurate macroscopic constitutive model of shape memory alloys has been developed. The features of this model are (1) energy-based phase transformation criterion, (2) one-dimensional phase transformation rule based on a micromechanical viewpoint, (3) dissipated energy with a form of a sum of two exponential functions, (4) duplication of the strain rate effect, and (5) adaptability to multi-phase transformation. This model is further improved to be able to express stress-strain relationships such that the reverse transformation starts at a higher stress than the martensitic transformation starts. Here, the ideal reversible transformation temperature is empirically described by a function of the martensite volume fraction. In this paper, an outline of our model is given, where the improvement is introduced. Then, it is shown that the model can quantitatively duplicate the major and minor hysteresis loops, strain rate effect, and asymmetry in tension and compression on the stress-strain relationship. And that it can also duplicate the stress-strain relationships having the reverse transformation start stress higher than the forward one.


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