A comparison study on the impact failure behavior of laminate and woven composites with consideration of strain rate effect and impact attitude

2021 ◽  
Vol 164 ◽  
pp. 107843
Author(s):  
Chunlin Du ◽  
Huanfang Wang ◽  
Zhenqiang Zhao ◽  
Lu Han ◽  
Chao Zhang
2012 ◽  
Vol 706-709 ◽  
pp. 799-804 ◽  
Author(s):  
Takashi Yokoyama

The impact compressive failure behavior of a unidirectional T700/2521 carbon/epoxy laminated composite in three principal material directions or fiber (1-), in-plane transverse (2-) and through-thickness (3-) directions is investigated on the conventional split Hopkinson pressure bar (SHPB). Cubic and rectangular block specimens with identical square cross section are machined from an about 10 mm thick composite laminate. The uniaxial compressive stress-strain curves up to failure at quasi-static and intermediate strain rates are measured on an Instron testing machine. It is shown that the ultimate compressive strength and strain exhibit no strain-rate effect in the 1-direction, but a slight strain-rate effect in the 2-and 3-direction over a range of strain rates from10-3to 103/s.


Author(s):  
Farhana Pervin ◽  
Weinong W. Chen ◽  
Tusit Weerasooriya

The body armor can protect the soldiers from penetrating and blunt injury during the war, but its prevention standard lacks the biomedical validity. To improve the protection gear and prevention strategies, we need valid input data in mathematical modeling at different impact loading conditions. Our aim is to provide the valid data for the computer modeling and simulation based on the injury levels. Dynamic mechanical behaviors of kidney tissues are needed as input data for the impact modeling of penetrating injury. Moreover, the knowledge of mechanical responses of kidney tissues is important for diagnosis, surgical simulation and training purposes. This work investigates the impact of strain rate effect of kidney tissue under compression. The dynamic response of kidney tissues is studied using Split Hopkinson pressure bar (SHPB) technique. We have modified the classical SHPB technique to characterize the mechanical behavior of kidney tissues at high strain-rate ranging from 1000 s−1 to 3000 s−1 by incorporating quratz-crystal technique and hollow transmission bar. We have also studied the quasi-static response of kidney tissues at three different strain-rates of 0.01 s−1, 0.1 s−1 and 1 s−1 as well as the intermediate strain rate at two different strain rates of 10 s−1 and 100s−1. The experiment results indicate the non-linear stress-strain response of materials. The kidney tissue stiffens evidently with increasing strain-rate.


2017 ◽  
Vol 36 (20) ◽  
pp. 1531-1541 ◽  
Author(s):  
Jiuzhou Zhao ◽  
Li Zhang ◽  
Licheng Guo ◽  
Yongqi Yang

A series of experiments on 3D angle-interlock carbon/epoxy woven composites were carried out using the split Hopkinson pressure bar and split Hopkinson tension bar. These tests were accomplished to investigate the strain rate effect of the dynamic compressive and tensile properties. The strain rate range is about 500/s to 1500/s for through-thickness compressive tests, 150/s to 600/s for in-plane compressive tests, and 600/s to 1000/s for in-plane tensile tests. The corresponding quasi-static properties are given for reference. The tested specimens were observed using optical microscope and scanning electron microscope. The main failure modes of the specimens include fiber breakage, fiber pull out and matrix crack. The compressive modulus of through-thickness direction is positively related to the strain rate. The compressive strength and modulus of in-plane direction shows a light fluctuation within the studied strain rate. It is found that the tensile strength and modulus of in-plane direction are negatively related to the strain rate.


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.


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