Study on cross-scale temperature effect and damage failure evolution constitutive model of phthalazine ether sulfone ketone

Abstract

Poly(phthalazine ether sulfone ketone) (PPESK) is a new type of thermoplastic resin materials with high temperature resistance and corrosion resistance. However, the failure evolution regularities of PPESK at different temperatures still remain poorly understood, which greatly limits the application of this composite. Therefore, quasi-static tensile/bending tests and microscanning microscopic characterization were used to study the multi-scale failure constitutive equation of PPESK. Based on cross-scale experimental observation methods, the spatial damage morphology of materials at different temperatures is explored, and the temperature boundary effect of PPESK is proposed to reveal the failure and failure mechanisms of materials in a wide temperature range. The initiation and evolution of pores at the micro scale of PPESK and the cumulative damage caused by craze propagation and cracking are essential factors of material failure, which also exhibit strong temperature sensitivity. The specific manifestation is the high-temperature viscous flow effect of the resin at the micro scale, as well as the gradual evolution trend of quasi-brittleness and viscoelastic-plasticity between the 295 K–472 K temperature range in the macro performance, which increases its plastic deformation ability by 1–5 times. Specifically, the mechanism of cross-scale micro-pore initiation and crack propagation was introduced, and a cross-scale, fully three-dimensional failure damage evolution constitutive model of PPESK was constructed for the first time in a wide temperature range. The secondary development of the material constitutive model in the finite element software was carried out, and the construction of the constitutive equation of the PPESK cross-scale failure was completed. Finally, the mapping relationship between the material's crack failure form, mechanical behavior, and the constitutive model was further verified by experiments. It is established that the proposed PPESK multi-scale failure constitutive model enables one to effectively describe the complex mechanical response and failure law of thermoplastic resin materials under temperature gradients. Moreover, this theoretical tool is promising for the design of independently controllable high-temperature resistant thermoplastic resin materials, thereby providing important guidance means for engineering applications.