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.

scholarly journals The Out-of-Plane Compression Response of Woven Thermoplastic Composites: Effects of Strain Rates and Temperature

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 264
Author(s):  
Shiyu Wang ◽  
Lihua Wen ◽  
Jinyou Xiao ◽  
Ming Lei ◽  
Xiao Hou ◽  
...  
Keyword(s):  
Strain Rate ◽  
Elevated Temperatures ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Dynamic Compression ◽  
Polyphenylene Sulfide ◽  
Thermoplastic Composites ◽  
Strain Rates ◽  
Wide Range ◽  
Out Of Plane

The dynamic mechanical response of high-performance thermoplastic composites over a wide range of strain rates is a challenging research topic for extreme environmental survivability in the field of aerospace engineering. This paper investigates the evolution of the dynamic properties of woven thermoplastic composites with strain rate and damage process at elevated temperatures. Out-of-plane dynamic-compression tests of glass-fiber (GF)- and carbon-fiber (CF)-reinforced polyphenylene sulfide (PPS) composites were performed using a split Hopkinson pressure bar (SHPB). Results showed that thermoplastic composites possess strain-rate strengthening effects and high-temperature weakening dependence. GF/PPS and CF/PPS composites had the same strain-rate sensitivity (SRS) below the threshold strain rate. The softening of the matrix at elevated temperatures decreased the modulus but had little effect on strength. Some empirical formulations, including strain-rate and temperature effects, are proposed for more accurately predicting the out-of-plane dynamic-compression behavior of thermoplastic composites. Lastly, the final failure of the specimens was examined by scanning electron microscopy (SEM) to explore potential failure mechanisms, such as fiber-bundle shear fracture at high strain rates and stretch break at elevated temperatures.

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 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.

Research on Dynamic Compression-Shear Behavior of Closed-Cell Aluminum Foam

2013 ◽  
Vol 423-426 ◽  
pp. 1648-1654
Author(s):  
Jiang Ren Lu ◽  
Jian Zhang ◽  
Xin Li Sun ◽  
Xing Hui Cai
Keyword(s):  
Shear Band ◽  
Strain Rate ◽  
Aluminum Foam ◽  
Dynamic Compression ◽  
Shear Loading ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
High Porosity ◽  
Finite Element Software ◽  
Closed Cell

In this paper, the dynamic compression-shear experiments on the closed-cell aluminum foam with porosity of 72%-92% are carried out by using improved split Hopkinson pressure bar. A high speed camera is used to observe the dynamic deformation behavior of the samples on the compression-shear loading. A finite element software ABAQUS is employed to simulate the dynamic compression-shear process of closed-cell aluminum foam. The results demonstrate that there is a compression-shear band on the samples during the compression-shear loading. The most severely damaged area of the material is on the compression-shear band; Low-porosity closed-cell aluminum foam has significant strain rate effect, however high-porosity closed-cell aluminum foam can ignore the strain rate effect. The yield stress of samples decreases with increasing samples angle, whereas shear stress increase with increasing samples angle, and also the corresponding time when the samples just begin to yield decreases with increasing samples angle.

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.

Sign in / Sign up

Export Citation Format

Share Document