Experimental characterisation of the dilation angle of polymers

A Comparative Study of Micromechanical Analysis Models for Determining the Effective Properties of Out-of-Autoclave Carbon Fiber–Epoxy Composites

“…This yield surface is represented as a − domain with a slope and intersects the vertical axis at ( = 0) = fined as The model is defined by two parameters: the friction angle measures t the yield surface, while the dilatancy angle ψ measures its expansion. The p the epoxy polymer matrix used in the carbon-fiber-reinforced composites we from the literature [54][55][56][57], as shown in Table 2. The fiber-matrix interface was modeled utilizing the cohesive zone mod defined according to a mixed-mode bilinear traction-separation law [58][59][60] cohesive elements at the fiber-matrix interface that are subject to a quadratic rion [61].…”

“…The model is defined by two parameters: the friction angle measures the slope of the yield surface, while the dilatancy angle ψ measures its expansion. The properties of the epoxy polymer matrix used in the carbon-fiber-reinforced composites were obtained from the literature [ 54 , 55 , 56 , 57 ], as shown in Table 2 .…”

Examining the Quasi-Static Uniaxial Compressive Behaviour of Commercial High-Performance Epoxy Matrices

“…A similar methodology was adopted to determine the dilation angle to that reported in [32], and the dilation angle was calculated from Equation (2). Representative radial and axial components of plastic strain vs. total axial strain obtained from the epoxy resin samples are shown in Figure 7.…”

“…The dilation angle values presented in Table 3 suggest that at such strain, plastic deformation occurs almost at a constant volume, similar to what was observed in ref. [32] for an untoughened resin. In addition, from Figure 8, considering the data scatter in dilation angle vs. plastic axial strain curves, no significant statistical difference can be identified across the different material systems.…”