A material property degradation model of composite laminates considering stress level

Author(s):  
Huidong Ma ◽  
Qiang Ma ◽  
Xuezong Bai ◽  
Jialiang Xu ◽  
Zongwen An
2014 ◽  
Vol 1064 ◽  
pp. 108-114 ◽  
Author(s):  
Jun Kang ◽  
Zhi Dong Guan ◽  
Zeng Shan Li ◽  
Zhun Liu

A three dimensional analysis model is developed on the fatigue life prediction of composite laminates based on a progressive damage analysis. This model consists of stress analysis, fatigue failure analysis and material property degradation. Teserpe’s failure criteria is used to fatigue damage analysis. Fiber tensile/compressive breakage, matrix tensile/compressive cracking, matrix/fiber shear failure and tension/compression delamination are considered in fatigue damage analysis. The methodologies of sudden degradation and gradual degradation are both applied in the material property degradation. The stiffness and strength gradual degradation is based on the Shokrieh fatigue model, which is based on fatigue test for unidirectional laminates. In order to consider the scatter of the material in the practical structures, the stiffness and strength of the material are randomly distributed using normal distribution in the numerical model. The progressive fatigue damage model is developed in finite element code ABAQUS through user subroutine UMAT, which can simulate the fatigue damage process. Fatigue life of different ply stacking sequences and geometries composite laminates under different cycle loading are predicted. The predicted fatigue life is in good agreement with the experimental results.


2000 ◽  
Author(s):  
John Whitcomb ◽  
Xiaodong Tang

Abstract This paper investigates the effects of geometric non-linearity and material property degradation models on the prediction of progressive failure analyses of woven composites under tensile and compressive loads. Preliminary results presented herein suggest that the degree of difficulty of conducting progressive failure analysis is largely a function of the degree of waviness. The large waviness material exhibits complex behavior and the predictions are very sensitive to the assumed degradation model. The low waviness composite, which is more representative of most structural weaves, does not exhibit such complex behavior, at least on the global scale.


2021 ◽  
Vol 15 ◽  
pp. 248-257
Author(s):  
Mohammed Bousfia ◽  
Mohammed Aboussaleh ◽  
Brahim Ouhbi

In this document, a hybrid procedure is constructed in order to predict the damage of a composite unidirectional laminate under random loading. This procedure is based on two pillars: a stiffness degradation model (SD-M) combined with an energy approach taking into account the effect of load ratio in addition to a system of equations generated by SSDQM method (Space State Differential Quadrature Method) which we have solved with a novel technic. The outputs of SSDQM method, previously serving for free vibration behavior analysis of composite structures, are used with those of SD-M model to predict damage failure of a composite laminate subjected to spectra loading. The results obtained correlate very well with experimental ones and an extensive comparison with other models validate the accuracy and convergence characteristics of this hybrid procedure.


2007 ◽  
Vol 334-335 ◽  
pp. 217-220
Author(s):  
Li Li Tong ◽  
Zhen Qing Wang ◽  
Bao Hua Sun

Numerical simulation for unidirectional hoop composite laminates under flexural loads was finished. The change of tensile and compressive stresses, the position of local crush and delamination and stiffness degradation were analyzed with parametric program compiled by APDL language in ANSYS. The results showed that composite laminate could bear the load continually after local crush and delamination. Displacements of calculated result with stiffness degradation model matched test results well.


Author(s):  
J. Nakai-Chapman ◽  
Y. H. Park ◽  
J. Sakai

Abstract Anisotropic composite materials have been extensively utilized in mechanical, automotive, aerospace and other engineering areas due to high strength-to-weight ratio, superb corrosion resistance, and exceptional thermal performance. As the use of composite materials increases, determination of material properties, mechanical analysis and failure of the structure become important for the design of composite structure. In particular, the fatigue failure is important to ensure that structures can survive in harsh environmental conditions. The non-homogeneous character of composites induces diverse failure modes of the constituent including fiber fracture, matrix cracking, fiber-matrix interface failure, and delamination. Non-homogeneity of composite materials makes their fatigue behavior very complex in comparison with traditional engineering materials. In this study, a progressive damage theory is extended to simulate fatigue failure of composite laminates under fatigue loading conditions. A residual material property degradation model was employed to predict fatigue damage due to arbitrary stress ratio without performing excessive quantities of testing. This generalized residual material property degradation rule is implemented into user subroutine USDFLD in ABAQUS through which material degradation states are updated over the progressive fatigue loading. The present computational method is verified by comparing the simulated results with the experimental data available in the literature.


2011 ◽  
Vol 21 (8) ◽  
pp. 1154-1185 ◽  
Author(s):  
D. C. Pham ◽  
X. S. Sun ◽  
V. B. C. Tan ◽  
B. Chen ◽  
T. E. Tay

This article presents progressive failure analysis of double-notched carbon/epoxy composite laminates with different scales. A numerical analysis strategy based on material property degradation method (MPDM) and cohesive elements (CE) is developed to model progressive failure of scaled double-notched composite laminates, where the material property degradation method is used to model the intralaminar failure and the cohesive elements are employed to account for the delamination at the interfaces. Different failure theories are considered in the material property degradation method–cohesive element approach and a comparative study of these failure theories is presented. The mesh dependency of the material property degradation method–cohesive element approach is investigated with different notch and element types for the double-notched composite laminates. Size scaling effects are also studied by traditional fracture models and the material property degradation method–cohesive element approach, significantly revealing a trend in strength reduction of notched composites with increasing specimen size. The predictions are compared with the experimental results and reasonably good agreement is observed.


2021 ◽  
Vol 15 ◽  
pp. 206-213
Author(s):  
Mohammed Bousfia ◽  
Mohammed Aboussaleh ◽  
Brahim Ouhbi

In this document, a hybrid procedure is constructed in order to predict the damage of a composite unidirectional laminate under random loading. This procedure is based on two pillars: a stiffness degradation model (SD-M) combined with an energy approach taking into account the effect of load ratio in addition to a system of equations generated by SSDQM method (Space State Differential Quadrature Method) which we have solved with a novel technic. The outputs of SSDQM method, previously serving for free vibration behavior analysis of composite structures, are used with those of SD-M model to predict damage failure of a composite laminate subjected to spectra loading. The results obtained correlate very well with experimental ones and an extensive comparison with other models validate the accuracy and convergence characteristics of this hybrid procedure.


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