A comparison of process-induced residual stresses and distortions in composite structures with different constitutive laws

Abstract

The popular analytical and numerical models to residual stresses and distortions in composite structures during curing are reviewed with emphases being placed on the numerical models with viscoelastic, path-dependent, CHILE constitutive laws, and corresponding numerical implementation into finite element analyses in this paper. A simple C-section composite part made of AS4/8552 prepreg, which has been investigated previously, was taken as an example to compare the difference in residual stresses and distortions with analytical model and numerical method with different constitutive laws. This paper mainly focuses on the effects of residual stresses generated at the different stages during curing on the finial distortions of composite structures for different constitutive laws, especially for effects of residual stresses generated in the rubbery stage on the final distortions. The results show that there is insignificant difference in the calculated residual stresses and distortions in C-section composite part induced during curing with different constitutive laws except the CHILE() law.

Electro-Mechanical Properties of Multilayer Graphene-Based Polymeric Composite Obtained through a Capillary Rise Method

“…The filler-to-matrix interface governs the load transfer mechanism, and for strain sensor applications, it influences the obtainment of a stable piezoresistive characteristic, over subsequent measurements, as well as in case of cyclic loading [19,20]. Nevertheless, process-induced defects in the composite, such as voids and filler agglomerates, may originate microcracks [21,22], which are enhanced by induced residual stresses and distortions caused by manufacturing and machining processes [23,24]. These defects result in a progressive deterioration of the mechanical properties of the composite for increasing or repetitive load cycles, and they limit the use of such composites in strain sensor applications because of the continuous increase of the electrical resistance of the material under stress [13,25,26].…”

Prediction Models for Distortions and Residual Stresses in Thermoset Polymer Laminates: An Overview

“…Ding et al, in 2015 [56], presented a three-dimensional finite element model for the prediction of residual stresses in composites implementing a user-defined material model in ABAQUS. In the year after, 2016, the same authors [57] investigated different constitutive models to predict the process-induced residual stresses in composites. Recently, researchers in 2016, 2018, and 2019 [58][59][60], compared elastic and viscoelastic numerical models for the curing-induced stresses in composites.…”

The Analysis of Residual Stresses in Layered Composites With [0°/90°] Layup

“…/ PNRPU Mechanics Bulletin 3 (2019) 17-26 20 (модель CHILE [20])» и вязкоупругая для прогнозирования остаточных напряжений для термореактивных полимерных композитов, вызванных процессом отверждения. В работах [20,21] было показано, что модель CHILE и вязкоупругая модель достаточно точно описывают поведение материала и могут быть надежно применены при моделировании поведения термореактивных полимерных композитов в процессе отверждения. В настоящей работе для описания поведения углеродно-эпоксидного композита (AS4/8552-1) во время затвердевания использовалась модель CHILE ввиду ее простоты.…”

“…Таким образом, существует вероятность зарождения микротрещин в образце в процессе изготовления, а так-же при сравнительно небольшой нагрузке во время эксплуатации. Результаты моделирования согласуются с выводами, указанными в [21], которые продемонстрировали инициирование трещин матрицы в композитном образце [0°/90°] в результате остаточных напряжений, полученных во время технологического цикла отверждения. Согласно данным, приведенным в техническом паспорте продукта, предел прочности при поперечном растяжении для отвержденного препрега AS4 /8552 составляет 81 МПа.…”