Rate-Dependent Behavior and Constitutive Model of Polycarbonate at Strain Rate from 10-5 to 103 S-1

2011 ◽  
Vol 117-119 ◽  
pp. 434-437
Author(s):  
Wen Jun Hu ◽  
Xi Cheng Huang ◽  
Fang Ju Zhang ◽  
Cheng Jun Chen
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Temperature Dependent ◽  
Static Tests ◽  
Rate Range ◽  
Rate Dependent ◽  
Dependent Behavior

Uni-axial quasi-static tests at strain rates 10-5, 10-4, 10-3,10-2 and 10-1 s-1 and dynamic compressive tests at strain rates 1679, 2769,5000 and 8200 s-1 have been carried out to study the mechanical behavior for polycarbonate used in the avigation industry. The stress–strain curves of polycarbonate in the strain-rate range from 10-5 to 8200 s-1 have been obtained. The effects of the strain rate on yield phenomenon and rate-dependent mechanical behavior are discussed. A plastic flow law based on the DSGZ rate-temperature-dependent constitutive model was used to describe the mechanical behavior of polycarbonate in the strain-rate range from 10-5 to 103 s-1. The results at the six strain rates are in excellent agreement with the experimental data, which illustrates that the constitutive model can describe the mechanical behavior for polycarbonate at low and high strain rates perfectly.

scholarly journals Extension of Flow Behaviour and Damage Models for Cast Iron Alloys with Strain Rate Effect

2020 ◽  
Author(s):  
Chuang Liu ◽  
Dongzhi Sun ◽  
Xianfeng Zhang ◽  
Florence Andrieux ◽  
Tobias Gerster
Keyword(s):  
Cast Iron ◽  
Constitutive Model ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Damage Model ◽  
Iron Alloys ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Damage Models ◽  
Rate Dependent

Abstract Cast iron alloys with low production cost and quite good mechanical properties are widely used in the automotive industry. To study the mechanical behavior of a typical ductile cast iron (GJS-450) with nodular graphite, uni-axial quasi-static and dynamic tensile tests at strain rates of 10− 4, 1, 10, 100, and 250 s− 1 were carried out. In order to investigate the effects of stress state, specimens with various geometries were used in the experiments. Stress–strain curves and fracture strains of the GJS-450 alloy in the strain-rate range of 10− 4 to 250 s− 1 were obtained. A strain rate-dependent plastic flow law based on the Voce model is proposed to describe the mechanical behavior in the corresponding strain-rate range. The deformation behavior at various strain rates is observed and analyzed through simulations with the proposed strain rate-dependent constitutive model. The available damage model from Bai and Wierzbicki is extended to take the strain rate into account and calibrated based on the analysis of local fracture strains. The validity of the proposed constitutive model including the damage model was verified by the corresponding experimental results. The results show that the strain rate has obviously nonlinear effects on the yield stress and fracture strain of GJS-450 alloys. The predictions with the proposed constitutive model and damage models at various strain rates agree well with the experimental results, which illustrates that the rate-dependent flow rule and damage models can be used to describe the mechanical behavior of cast iron alloys at elevated strain rates.

Tensile Stress-Strain Curves Modeling of Four Kinds of Solders with Temperature and Rate Dependence

2005 ◽  
Vol 297-300 ◽  
pp. 905-911 ◽  
Author(s):  
Xu Chen ◽  
Li Zhang ◽  
Masao Sakane ◽  
Haruo Nose
Keyword(s):  
Tensile Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Rate Dependence ◽  
Strain Rates ◽  
Stress Strain ◽  
Rate Range

A series of tensile tests at constant strain rate were conducted on tin-lead based solders with different Sn content under wide ranges of temperatures and strain rates. It was shown that the stress-strain relationships had strong temperature- and strain rate- dependence. The parameters of Anand model for four solders were determined. The four solders were 60Sn-40Pb, 40Sn-60Pb, 10Sn-90Pb and 5Sn-95Pb. Anand constitutive model was employed to simulate the stress-strain behaviors of the solders for the temperature range from 313K to 398K and the strain rate range from 0.001%sP -1 P to 2%sP -1 P. The results showed that Anand model can adequately predict the rate- and temperature- related constitutive behaviors at all test temperatures and strain rates.

scholarly journals Mechanical Behaviors of Flax Fiber-Reinforced Composites at Different Strain Rates and Rate-Dependent Constitutive Model

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 854 ◽  
Author(s):  
Dayong Hu ◽  
Linwei Dang ◽  
Chong Zhang ◽  
Zhiqiang Zhang
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Flax Fiber ◽  
Fiber Reinforced Composites ◽  
Strain Rates ◽  
Reinforced Composites ◽  
Dynamic Mechanical ◽  
Rate Dependent ◽  
Dynamic Mechanical Behavior

Flax fiber-reinforced composites (FFRCs) exhibit excellent environmentally friendly qualities, such as light weight, low cost, recyclability, and excellent mechanical properties. Understanding the dynamic mechanical behavior of FFRCs could broaden their potential applications in lightweight, crashworthy, and impact-critical structures. This study presents a study on the fabrication of FFRCs by vacuum-assisted resin infusion. The dynamic stress–strain responses of the fabricated specimens at strain rates ranging from 0.006 s-1 to 2200 s-1 were evaluated using quasi-static tests and the Split–Hopkinson pressure bar (SHPB). The results indicated that the FFRC exhibited superior strain rate sensitivity. Final deformation photographs and scanning electron micrographs clearly revealed the damage evolution of the FFRC specimens, as well as various failure mechanisms, including fiber–matrix debonding, fiber pull-out, and fiber fracture at different strain rates. On the basis of the experimental results, a simplified Johnson–Cook model was established to describe the strain-rate dependent constitutive model of FFRC. The validation of the suggested constitutive model was embedded in the finite element simulations and could well repeat the strain wave observed from the experiment results. Finally, the quasi-static compression and drop-hammer impact of pyramidal lattice structures with FFRC cores were investigated both numerically and experimentally, proving the effectiveness of the simplified Johnson–Cook model. This study could potentially contribute to a deeper understanding of the dynamic mechanical behavior of FFRCs and provide fundamental experimental data for future engineering applications.

scholarly journals Effect of Strain Rate on Compressive Behavior of a Zr-Based Metallic Glass under a Wide Range of Strain Rates

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2861
Author(s):  
Wenqing Li ◽  
Tieqiang Geng ◽  
Shaofan Ge ◽  
Zhengwang Zhu ◽  
Long Zhang ◽  
...  
Keyword(s):  
Amorphous Alloy ◽  
Yield Strength ◽  
Strain Rate ◽  
Amorphous Alloys ◽  
High Strain ◽  
Strain Rate Range ◽  
Strain Rate Effect ◽  
Strain Rates ◽  
Compressive Behavior ◽  
Rate Range

The strain rate effect on the mechanical behavior of amorphous alloys has aroused general interest. Most studies in this area have focused on quasi-static and high strain-rate compressive deformations. However, experimental results have been few, or even non-existent, under a moderate strain-rate loading. This article extends the traditional split Hopkinson pressure bar (SHPB) technique to characterize compressive deformation of an amorphous alloy at medium strain rates. The compressive behavior of Zr65.25Cu21.75Al8Ni4Nb1 amorphous alloy shows a negative strain rate effect on the yield strength with a quasi-static, moderate to high strain-rate range, and the fracture angle increases from 44° at 10−5 s−1 to 60° at 4000 s−1 as strain rate increases. Herein, we introduce a modified cooperative shear model to describe the compressive behavior of the current amorphous alloy under a broad strain rate range. The model predicts that the normalized yield strength will linearly descend with logarithmic strain rate when the strain rate is less than a critical strain rate, however, which rapidly decreases linearly with the square of the strain rate at high strain rates. The predicted data of the model are highly consistent with the current experimental results. These findings provide support for future engineering applications of amorphous alloys.

Modeling and Testing Strain Rate-Dependent Tensile Strength of Carbon/Epoxy Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1418-1421 ◽  
Author(s):  
Gui Ping Zhao ◽  
Zheng Hao Wang ◽  
Jian Xin Zhang ◽  
Qiao Ping Huang
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Split Hopkinson Tensile Bar ◽  
Rate Dependent ◽  
Dependent Behavior ◽  
Split Hopkinson ◽  
Rate Experiment ◽  
Epoxy Matrix Composite ◽  
Dependent Model

Tensile strength is an important material property and usually can be determined experimentally. The strain rate dependent behavior of T300 carbon/epoxy matrix composite was characterized over a wide strain rate range (10×10-5 s-1to10×104s-1). The low to moderate strain rate experiments were carried out on a MTS machine, while the high strain rate experiment was conducted with a split Hopkinson tensile bar. A rate dependent model was introduced to simulate the material response. Two kinds of stacking sequence of composite specimens [(45/-45)4]s and [(0/45/90/-45)2]s were tested at different strain rates, and the results were used to determine parameters of the model. The predictions of the model showed to agree fairly well with the experimental results. The tensile strength and initial elastic modulus of the composites increase when the strain rate increases.

Compressive strength of iceberg ice

2003 ◽  
Vol 81 (1-2) ◽  
pp. 191-200 ◽  
Author(s):  
S J Jones ◽  
R E Gagnon ◽  
A Derradji ◽  
A Bugden
Keyword(s):  
Grain Size ◽  
Compressive Strength ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Air Bubbles ◽  
Strain Rates ◽  
Thin Sections ◽  
Rate Range ◽  
A Value ◽  
Wide Range

The uniaxial compressive strength of iceberg ice was determined over a wide range of strain rates from 10–8 to 10+1 s–1 at –10°C. It was found that for strain rates less than 10–4 s–1, strength increased in a power-law manner with strain rate. Above 10–4 s–1, the strength was essentially constant at 4 MPa, dropping slightly between 10–3 and 10–1 s–1, before rising again to a value of about 10 MPa at 10+1 s–1. Thin sections of the ice revealed a small grain size of about 3.5 mm and elongated air bubbles with a ratio of length to width of about 10. In the practical strain-rate range of interest, the maximum failure stress observed was 4.8 MPa. PACS No.: 62.20

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