An analytical model for evaluating the buckling, delamination propagation, and failure behaviors of delaminated composites under uniaxial compression

2019 ◽  
Vol 223 ◽  
pp. 110937 ◽  
Author(s):  
Kangkang Wang ◽  
Libin Zhao ◽  
Haiming Hong ◽  
Yu Gong ◽  
Jianyu Zhang ◽  
...  
2013 ◽  
Vol 577-578 ◽  
pp. 497-500 ◽  
Author(s):  
Vitalijs Pavelko ◽  
Igors Pavelko ◽  
Maxim Smolyaninov

An accurate 1D model of post-buckling deformation of a thin sub-laminate of layered composite is develloped using nonlinead theory of slender plate. The strain energy realize rate at delamination propagation is obtained via the elliptical integrals. A model of fracture buckled sub-laminate is implemented and used for general analysis of progressive damage of composite


2000 ◽  
Author(s):  
Hurang Hu ◽  
Weidong Xie ◽  
Suresh Sitaraman

Abstract One of the most common failure modes in multi-layered electronic packaging structures is interfacial delamination. The objective of this research is to examine the possibilities of interfacial delamination in a next-generation electronic packaging structure under thermal loading. A sophisticated analytical model has been developed to determine energy release rate and stress intensity factor for delamination propagation. The model takes into consideration the temperature-dependent material properties as well as direction-dependent material properties. Although delamination between two adjacent layers is studied, the model takes into consideration the effect of all dielectric, metallization, and substrate layers in the multi-layered structure. Assuming that an initial delamination exists between the base layer and the Copper metallization layer, the present work studies the propagation of delamination. In the analytical model, the base layer is modeled as an orthotropic thermo-elastic material. Copper and the polymer dielectric materials are modeled as isotropic thermo-elastic material. For the Copper/base layer interface, the variation of bimaterial constant (ε) with temperature is obtained through the analytical model. The effect of some key parameters, such as materials Young’s modulus, coefficient of thermal expansion, and the base layer thickness on energy release rate is presented. Design recommendations for improved thermo-mechanical reliability are proposed.


2002 ◽  
Vol 749 ◽  
Author(s):  
Alex A. Volinsky

ABSTRACTThere are many different stress relief mechanisms observed in thin films. One of the mechanisms involves film debonding from the substrate. In the case of tensile residual stress a network of through-thickness cracks forms in the film. In the case of compressive residual stress thin film buckling and debonding from the substrate in the form of blisters is observed. The buckling delamination blisters can be either straight, or form periodic buckling patterns commonly known as telephone cord delamination morphology.The mechanics of straight-sided blisters is well understood. Current study relies on the in-situ observation of phone cord delamination propagation in different thin film/substrate systems. Both straight and phone cord delaminations are shown to simultaneously propagate in the same film system. Straight-sided blisters propagate several times faster than the phone cords, and may be followed by thin film fracture along the line of maximum film buckling amplitude. Phone cord delaminations originally start as straight-sided blisters, but then deviate to the periodic phone cord geometry due to the fact that the compressive residual stress in the film is biaxial. Digital analysis of motion recordings shows that partial crack “healing” is present at the curved portions of the phone cords due to the “secondary” buckling pushing thin film back to the substrate. These experimental observations allow for the correct interpretation of the telephone cord delamination morphology.


2020 ◽  
Vol 117 (49) ◽  
pp. 31002-31009
Author(s):  
Bolei Deng ◽  
Siqin Yu ◽  
Antonio E. Forte ◽  
Vincent Tournat ◽  
Katia Bertoldi

Domain walls, commonly occurring at the interface of different phases in solid-state materials, have recently been harnessed at the structural scale to enable additional modes of functionality. Here, we combine experimental, numerical, and theoretical tools to investigate the domain walls emerging upon uniaxial compression in a mechanical metamaterial based on the rotating-squares mechanism. We first show that these interfaces can be generated and controlled by carefully arranging a few phase-inducing defects. We establish an analytical model to capture the evolution of the domain walls as a function of the applied deformation. We then employ this model as a guideline to realize interfaces of complex shape. Finally, we show that the engineered domain walls modify the global response of the metamaterial and can be effectively exploited to tune its stiffness as well as to guide the propagation of elastic waves.


1981 ◽  
Vol 48 (4) ◽  
pp. 816-824 ◽  
Author(s):  
G. U. Fonseka ◽  
D. Krajcinovic

This part of the paper focuses on the application of the analytical model developed in Part 1 on the uniaxial tension, uniaxial compression, and plane problems (including rotating strain fields and unproportional loading). Identification of the material parameters is discussed in view of the derived results.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Feng He ◽  
Zhenwei Wang ◽  
Yangfeng Zhao ◽  
Gaofeng Song ◽  
Bowen Liu

The electrical charge characteristic of rock materials under compression is an important index for predicting the development of rock fractures and the failure of engineering structures. However, the charge behaviours of a preexisting rock sample have not been studied in depth. In this study, sandstone samples with a single fabricated precrack at different angles of inclination are prepared. The uniaxial compression tests are performed to study the charge behaviours associated with the initiation and propagation of secondary cracks, the mechanical properties, and the progressive failure of stressed rock samples. An improved analytical model based on the maximum tensile stress failure theory for brittle materials is also proposed for determining the crack growth paths of the single precrack rock samples under uniaxial compression. The friction factors of crack surfaces are computed. The results show that the step functions on the curves of charge accumulation over time correspond to the fluctuation of stress, indicating the initiation of microcracks. The sample with a crack inclination angle of π / 4 shows the largest amount of both the first charge and the total accumulation. The analytical model shows a positive relationship between the crack face friction factors and the charge accumulation. The analytical solution of the crack development angles shows good agreement with the experimental results. This work may provide reference for the similar studies regarding the correlation of charging behaviours to the compressed rock materials.


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