A bi-directional damage model for matrix cracking evolution in composite laminates under fatigue loadings

2020 ◽  
Vol 134 ◽  
pp. 105417 ◽  
Author(s):  
Wenxuan Qi ◽  
Weixing Yao ◽  
Haojie Shen
Keyword(s):  
Composite Laminates ◽  
Damage Model ◽  
Matrix Cracking

scholarly journals 3D Progressive Failure Modeling of Drop-Weight Impact on Composite Laminates

2018 ◽  
Author(s):  
DC Pham
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Progressive Failure ◽  
Damage Model ◽  
Matrix Cracking ◽  
Structural Level ◽  
Velocity Impact ◽  
Drop Weight ◽  
Weight Impact ◽  
The Impact

Composite laminates are susceptible to out-of-plane impact loads due to the lack of reinforcement in the through-thickness direction. Unlike the localized damage induced by a high velocity impact where the incident energy is dissipated near a contact area, low velocity impact damage involves multiple failure mechanisms such as matrix cracking, fiber breakage, and widespread interface delaminations. Depending on the extent of damage, significant reduction in the load-bearing capability of the structure has been observed. The prediction of composite impact damage resistance by a reliable progressive damage analysis tool is essential to reduce intensive and expensive certification tests at structural level. In this work, an enhanced explicit 3D damage model is implemented via VUMAT in Abaqus to perform a drop-weight impact simulation of a [454/04/-454/904]s Hexply AS4/8552 composite laminate. The impact-induced damage and its extent are captured by a 3D Continuum Damage Model (CDM) coupled with an energy driven failure mechanism. The developed module provides a unified solution process for the impact response prediction followed by the residual strength prediction under compression within an explicit solver. Two examples are selected to demonstrate the capability of the progressive failure analysis under dynamic and static loading: 1) a drop-weight test; and 2) an open-hole tension test. Numerical predictions from the developed VUMAT are compared with the test data and predictions using the open source CompDam code developed by NASA.

A multidirectional damage model for fiber-reinforced plastic laminates under static load

2019 ◽  
Vol 54 (2) ◽  
pp. 153-166
Author(s):  
Wenxuan Qi ◽  
Weixing Yao ◽  
Haojie Shen
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Matrix Cracking ◽  
Fiber Reinforced ◽  
Damage Mechanisms ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Plastic Laminates

A multidirectional damage model based on continuum damage mechanics for fiber-reinforced composite laminates is proposed in this paper. The influence of three main damage mechanisms, including transverse matrix cracking, local delamination, and fiber breakage, on the multidirectional stiffness properties of composite laminates is analyzed by introducing macro phenomenological damage variables. Then the mechanical behavior of elementary ply in laminates is modeled based on these damage variables. Besides, relations between micro-level damage variables and macro-level damage variables are established. Damage evolution laws of the three damage mechanisms are proposed to predict the degradation of multidirectional stiffness and failure strength of composite laminates under quasi-static loading. The experiment of cross-ply glass fiber-reinforced plastic laminates is carried out, and the prediction results show good agreement with the experimental results.

A micromechanics-based damage model for compressive behavior analysis of impacted composite laminates

2019 ◽  
Vol 29 (3) ◽  
pp. 369-387 ◽  
Author(s):  
Xiaofei Lou ◽  
Xuecheng Han ◽  
Hongneng Cai
Keyword(s):  
Compressive Strength ◽  
Impact Loading ◽  
Composite Laminates ◽  
Failure Mechanisms ◽  
Damage Model ◽  
Failure Criteria ◽  
Matrix Cracking ◽  
Compressive Behavior ◽  
Isotropic Composite ◽  
The Matrix

The compressive strength of composite laminates decreases seriously after being subjected to impact loading, which is an important item to be considered in the usage of composite material. In this paper, a micromechanics-based damage model is proposed to study the compressive behavior of impacted composite laminates. The micro stresses of fiber and matrix are calculated by stress amplification factors and then used to judge the failure mechanisms according to corresponding physical failure criteria. A progressive damage model based on different failure statuses of constituents is established to study the degradation of material properties. The bi-linear cohesive model is used in the research of delamination onset and propagation. The compressive behaviors of quasi-isotropic composite laminates subjected to different impact energies are investigated by this proposed method. Good agreements in terms of structure responses, failure mechanisms, and residual compressive strengths are obtained between numerical results and experimental data. The matrix cracking and delamination caused by impact loading are responsible for the initiation and propagation of buckling, which leads to the final collapse of entire laminates. Based on the numerical investigations of material parameters, the increment of mode II interlaminar fracture toughness is capable of improving the residual compressive strength significantly.

A Damage Model Containing Delamination in Composite Laminates

2006 ◽  
Vol 324-325 ◽  
pp. 43-46
Author(s):  
Yu Pu Ma ◽  
Xin Zhi Lin ◽  
Qing Fen Li ◽  
Zhen Li
Keyword(s):  
Composite Laminates ◽  
Damage Model ◽  
Laminated Composite ◽  
Shear Lag ◽  
Analysis Model ◽  
Transverse Cracks ◽  
Transverse Cracking ◽  
Stiffness Reduction ◽  
Laminated Composite Materials ◽  
Modulus Reduction

When stress is high, delaminate damage can be induced by transverse cracks. A complete parabolic shear-lag damage model containing delamination induced by transverse cracks is therefore proposed and applied to predict the stiffness reduction by transverse cracking in cross-ply laminated composite materials. The predictions of the complete parabolic shear-lag analysis model, the incomplete parabolic shear-lag analysis model, and the complete parabolic shear-lag damage model containing delamination proposed in this paper have been compared. Results show that the young’s modulus reduction values obtained by our analysis model are better agreement with the experimental ones than other models.

Numerical Investigation of a Stiffened Panel Subjected to Low Velocity Impacts

2015 ◽  
Vol 665 ◽  
pp. 277-280 ◽  
Author(s):  
Aniello Riccio ◽  
S. Saputo ◽  
A. Sellitto ◽  
A. Raimondo ◽  
R. Ricchiuto
Keyword(s):  
Numerical Investigation ◽  
Composite Laminates ◽  
Mechanical Response ◽  
Numerical Study ◽  
Fem Analysis ◽  
Matrix Cracking ◽  
Stiffened Panel ◽  
Low Velocity ◽  
Formation And Evolution ◽  
The Impact

The investigation of fiber-reinforced composite laminates mechanical response under impact loads can be very difficult due to simultaneous failure phenomena. Indeed, as a consequence of low velocity impacts, intra-laminar damage as fiber and matrix cracking and inter-laminar damage, such as delamination, often take place concurrently, leading to significant reductions in terms of strength and stability for composite structure. In this paper a numerical study is proposed which, by means of non-linear explicit FEM analysis, aims to completely characterize the composite reinforced laminates damage under low velocity impacts. The numerical investigation allowed to obtain an exhaustive insight on the different phases of the impact event considering the damage formation and evolution. Five different impact locations with the same impact energy are taken into account to investigate the influence on the onset and growth of damage.

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