Study on strain-rate-dependent behaviour and constitutive model of long glass fibre reinforced polypropylene composite

The diffusion influence of seawater on the static and interlayer cracking properties of a polyvinyl chloride foam sandwich structure is investigated in this study. After soaking specimens in seawater for various durations, various comparison tests are performed to investigate the effects of seawater. Compression tests for H60 and H200 polyvinyl chloride foam specimens are conducted to study strength and modulus degradation, and the results show that immerging time and temperature have significant effects on polyvinyl chloride foam properties. Tensile tests for glass-fibre-reinforced plastic panels, four-point bending tests and double cantilever bending tests for polyvinyl chloride foam sandwich specimens are also performed. The results show that seawater immerging treatment has a noticeable influence on glass-fibre-reinforced plastic tensile properties and interlayer critical energy release rate values, but has almost no effect on bending properties of foam sandwich specimen. Furthermore, a rate-dependent phenomenon is observed in double cantilever bending tests, in which higher loading rate will lead to larger critical energy release values. Numerical simulation is also performed to illustrate the cracking process of double cantilever bending tests and shows a certain accuracy. The simulation also demonstrates that the viscoelasticity of foam material after immerging treatment results in the rate-dependent characterization of double cantilever bending tests.

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Energy absorption behaviour of different grades of steel sheets using a strain rate dependent constitutive model

Thin-Walled Structures ◽

10.1016/j.tws.2016.11.005 ◽

2017 ◽

Vol 111 ◽

pp. 9-18 ◽

Cited By ~ 2

Author(s):

Pundan K. Singh ◽

Anindya Das ◽

S. Sivaprasad ◽

Pinaki Biswas ◽

Rahul K. Verma ◽

...

Keyword(s):

Constitutive Model ◽

Strain Rate ◽

Energy Absorption ◽

Steel Sheets ◽

Rate Dependent

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

10.21203/rs.3.rs-113055/v1 ◽

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.

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