An empirical strain rate-dependent constitutive relationship for glass-fibre reinforced epoxy and pure epoxy

1995 ◽  
Vol 33 (4) ◽  
pp. 201-210 ◽  
Author(s):  
T.E. Tay ◽  
H.G. Ang ◽  
V.P.W. Shim
Keyword(s):  
Strain Rate ◽  
Glass Fibre ◽  
Constitutive Relationship ◽  
Pure Epoxy ◽  
Rate Dependent ◽  
Glass Fibre Reinforced

scholarly journals Seawater effects on static loads and interlayer cracking performance for polyvinyl chloride foam-cored sandwich composites

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880734
Author(s):  
Jian He ◽  
Dongyuan Xie ◽  
Qichao Xue ◽  
Yangyang Zhan
Keyword(s):  
Energy Release ◽  
Polyvinyl Chloride ◽  
Glass Fibre ◽  
Critical Energy ◽  
Bending Tests ◽  
Rate Dependent ◽  
Reinforced Plastic ◽  
Glass Fibre Reinforced Plastic ◽  
Glass Fibre Reinforced ◽  
Cantilever Bending

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.

Investigation of the strain rate hardening behaviour of glass fibre reinforced epoxy under blast loading

2020 ◽  
pp. 095440622093632
Author(s):  
Mohamed A Louar ◽  
Bachir Belkacem ◽  
Hamza Ousji ◽  
Lincy Pyl ◽  
John Vantomme
Keyword(s):  
Dynamic Response ◽  
Strain Rate ◽  
Glass Fibre ◽  
Blast Waves ◽  
Image Correlation ◽  
Model Parameters ◽  
Correlation Technique ◽  
Hardening Model ◽  
Glass Fibre Reinforced ◽  
Strain Rate Hardening

This work investigates the use of blast loadings and inverse modeling for the identification of the strain rate hardening model parameters of fibre reinforced polymers. An experimental setup allowing the generation of known and predictable blast waves, leading to repeatable dynamic response in composite plates and the measurement of the displacement and strain fields, is developed. The dynamic response of the plates is measured by means of high-speed cameras and a 3D digital image correlation technique. A suitable numerical model that is able to reproduce the experimental conditions and predict the blast response of the plates is developed. Finally, the experimental measurements and the numerical calculation are combined through an inverse method in order to identify the strain rate hardening model parameters of the tensile and shear strengths of glass fibre reinforced epoxy.

A strain rate dependent constitutive model for clays at residual strength

1998 ◽  
Vol 35 (2) ◽  
pp. 364-373 ◽  
Author(s):  
AMP Wedage ◽  
N R Morgenstern ◽  
D H Chan
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Residual Strength ◽  
Plasticity Theory ◽  
Constitutive Relationship ◽  
Plastic Strain Rate ◽  
Flow Rule ◽  
Rate Dependent ◽  
Dependent Part ◽  
Rate Effects

Plasticity theory is extended to incorporate strain rate effects on the residual shear strength of clays. The clay is assumed to behave elastically before yielding and then in a perfectly plastic manner with no volume change during yielding. The Mohr-Coulomb failure criterion is used in the rate-dependent model in which the strain rate affects the mobilized effective friction angle of the material. During initial yielding and subsequent plastic deformation, the stress and strain states at a point will satisfy the rate-dependent yield function (loading function). When the effective plastic strain rate decreases to a threshold strain value, the loading surface moves, or collapses, to the static yield surface. A constant volume flow rule is used to calculate plastic deformation. The computed stress-strain relationship is formulated in two parts, namely a rate-independent part and a rate-dependent part. The rate-independent part is the same as that used in classical elastoplastic formulations, whereas the rate-dependent part is dependent on the current strain rate of the material. The use of the model is illustrated using a numerical example simulating a two-dimensional plane strain test.Key words: constitutive relationship, finite element, plasticity theory, pre-sheared clay, rate effects, residual strength.

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