Strain rate effect on the out-of-plane dynamic compressive behavior of metallic honeycombs: Experiment and theory

2015 ◽  
Vol 132 ◽  
pp. 644-651 ◽  
Author(s):  
Yong Tao ◽  
Mingji Chen ◽  
Haosen Chen ◽  
Yongmao Pei ◽  
Daining Fang
Keyword(s):  
Strain Rate ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Compressive Behavior ◽  
Out Of Plane

Strain Rate Effect on Mechanical Behavior of Metallic Honeycombs Under Out-of-Plane Dynamic Compression

2015 ◽  
Vol 82 (2) ◽  
Author(s):  
Yong Tao ◽  
Mingji Chen ◽  
Yongmao Pei ◽  
Daining Fang
Keyword(s):  
Strain Rate ◽  
Present Model ◽  
Dynamic Compression ◽  
Strain Rate Effect ◽  
Numerical Results ◽  
Rate Effect ◽  
Plateau Stress ◽  
Parent Materials ◽  
Wide Range ◽  
Out Of Plane

Although many researches on the dynamic behavior of honeycombs have been reported, the strain rate effect of parent materials was frequently neglected, giving rise to the underestimated plateau stress and energy absorption (EA). In this paper, the strain rate effect of parent materials on the out-of-plane dynamic compression and EA of metallic honeycombs is evaluated by both numerical simulation and theoretical analysis. The numerical results show that the plateau stress and the EA increase significantly if the strain rate effect is considered. To account for the strain rate effect, a new theoretical model to evaluate the dynamic compressive plateau stress of metallic honeycombs is proposed by introducing the Cowper–Symonds relation into the shock theory. Predictions of the present model agree fairly well with the numerical results and existing experimental data. Based on the present model, the plateau stress is divided into three terms, namely static term, strain rate term, and inertia term, and thus the influences of each term can be analyzed quantitatively. According to the analysis, strain rate effect is much more important than inertia effect over a very wide range of impact velocity.

Strain Rate Effect on Out of Plane Shear Strength of Fiber Composites

2007 ◽  
Vol 345-346 ◽  
pp. 725-728
Author(s):  
Jia Lin Tsai ◽  
Jui Ching Kuo
Keyword(s):  
Shear Strength ◽  
Strain Rate ◽  
Shear Strain ◽  
Fiber Composites ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Strength Analysis ◽  
Shear Strain Rate ◽  
Plane Shear ◽  
Out Of Plane

This research aims to investigate strain rate effect on the out of plane shear strength of unidirectional fiber composites. Both glass/epoxy and graphite/epoxy composites were considered in this study. To demonstrate strain rate effect, composite brick specimens were fabricated and tested to failure in the transverse direction at strain ranges from 10-4/s to 700/s. Experimental observations reveal that the main failure mechanism of the specimens is the out of plane shear failure taking place on the plane oriented around 30 to 35 degree to the loading direction. The corresponding out-of-plane shear strength was obtained from the uniaxial failure stress through Mohr-Coulomb strength analysis. In addition, the associated shear strain rate on the failure plane was calculated through the coordinate transformation law. Results show that the out-plane shear strength increases with the increment of the shear train rates. A semi-logarithmic function expressed in terms of the normalized shear strain rate was employed to describe the rate dependence of the out-plane shear strength.

Dynamic out-of-plane compressive failure mechanism of C/C composite: Strain rate effect on the defect propagation and microstructure failure

2021 ◽  
pp. 1-31
Author(s):  
Fei Guo ◽  
Qingguo Fei ◽  
Yanbin Li ◽  
Nikhil Gupta
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Failure Mechanism ◽  
Maximum Stress ◽  
Testing Machine ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Compressive Failure ◽  
Macro Scale ◽  
Out Of Plane

Abstract Out-of-plane compression experiments with the strain rate from 0.0001/s to 1000/s are performed on 3D fine weave pierced Carbon/Carbon (C/C) composite using a universal testing machine, a high-speed testing machine, and a split Hopkinson pressure bar (SHPB). The compressive failure mechanism of the composite is analyzed by multi-scale analysis method, which ranges from micro-scale defect propagation, through meso-scale microstructure failure, to macro-scale material failure. In order to predict the out-of-plane compressive properties of 3D fine weave pierced C/C composite at different strain rates, a strain-rate-dependent compressive constitutive model is proposed. The results show that the out-of-plane compressive behavior of the 3D fine weave pierced C/C composite is sensitive to strain rate. With increasing the strain rate, the initial compressive modulus, the maximum stress and the strain at the maximum stress increase. The difference in mechanical behavior between quasi-static and high strain rate compression is owing to the strain rate effect on the defect propagation of the 3D fine weave pierced C/C composite. The proposed constitutive model matches well with the experimental data.

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