• Title/Summary/Keyword: hashin failure

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Progressive Damage Modeling of Inter and Intra Laminar Damages in Open Hole Tensile Composite Laminates (오픈 홀 인장 복합 재료 적층판에서 층간 및 내부 손상에 대한 점진적 손상 모델링)

  • Khalid, Salman;Kim, Heung Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.4
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    • pp.233-240
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    • 2019
  • Open-hole tensile tests are usually performed to measure the tensile strengths of composites as they are an essential parameter for designing composite structures. However, correctly modeling the tensile test is extremely challenging as it involves various damages such as fiber and matrix damage, delamination, and debonding damage between the fiber and matrix. Therefore, a progressive damage model was developed in this study to estimate the in-plane failure and delamination between the fiber and matrix. The Hashin damage model and cohesive zone approach were used to model ply and delamination failures. The results of the present model were compared with previously published experimental and numerical findings. It was observed that neglecting delamination during finite element analysis led to overestimation of tensile strength.

Estimating Tensile Strengths of CFRP Laminates Having Various Stacking Sequences (다양한 적층을 갖는 CFRP 적층판의 인장강도 예측)

  • Park, Chan Yik;Lee, Myung-Keon;Kim, Sang-Yong;Jang, Se-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.5
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    • pp.309-316
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    • 2022
  • This paper presents nonlinear numerical analysis results which were compared with the tested tensile strengths of CFRP(Carbon Fiber Reinforced Plastic) laminates with 14 different stacking sequences. The composite laminate coupons were cured under an autoclave pressure using resin-impregnated unidirectional tapes. The nonlinearity of the matrix was considered for the analysis, which was obtained from lamina tests. The Hashin failure criteria and progressive failure analysis were used for the nonlinear finite element analysis. The comparison results show that the current approach is acceptable to predict the tensile strengths of the CFRP laminate coupons with various stacking sequences and no damage. However, it is not acceptable to predict the tensile strengths of the laminate specimens with a center hole.

Strength Analysis for the Plate System of the Mark III Cargo Containment (Mark III 방열 판 구조물의 파손 강도 평가에 관한 연구)

  • Jeong, Han-Koo;Yang, Young-Soon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.625-633
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    • 2014
  • Mark III CCS plate is considered in this paper to perform its strength assessment. Mark III CCS plate is designed and constructed by stacking various non-metallic engineering materials such as plywood, triplex and reinforced PU foam that are supported by series of mastic upon inner steel hull structure. From the viewpoint of structural analysis, this plated structure is treated as a laminated anisotropic structure. Commercially available general purpose finite element analysis programs such as MSC PATRAN and MARC are used to develop the finite element (FE) model of the Mark III CCS plate. Because of the characteristics of LNG cargo that the Mark III CCS plate deals with, it is subjected to a wide range of temperature variations, i.e. about $-163^{\circ}C$ to $20^{\circ}C$. Different material properties of the Mark III CCS plate at these temperature levels are considered in the FE model. Using the developed FE model, strength assessment procedure is developed incorporating various anisotropic failure criteria such as Hashin, Hill, Hoffman, Maximum stress and Tsai-Wu. The strength assessment is performed within the initial failure state of the Mark III CCS plate and, as a result, failure details such as failure locations and loads are identified.

Progressive Damage Analysis of Plain Weave Fabric CFRP Orthogonal Grid Shell Under Bending Load (굽힘 하중을 받는 평직물 CFRP 직교 격자 쉘의 점진적 손상 해석)

  • Lim, Sung June;Baek, Sang Min;Kim, Min Sung;Park, Min Young;Park, Chan Yik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.4
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    • pp.256-265
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    • 2019
  • In this paper, the progressive damage of an orthogonal grid shell fabricated with plain weave fabric CFRP under bending load was investigated. The orthogonal grids were cured with the bottom composite shell. Progressive damage analysis of an orthogonal grid shell under bending was performed using nonlinear finite element method with Hashin-Rotem failure criterion and Matzenmiller-Lubliner-Taylor(MLT) model. In addition, the three - point bending test for the structure was carried out and the test results were compared with the analysis results. The comparison results of the strain and displacement agreed well. The damage area estimated by the progressive damage analysis were compared with the visual inspection and ultrasonic non-destructive inspection.

Analysis of the Segment-type Ring Burst Test Method for the Mechanical Property Evaluation of Cylindrical Composite Pressure Vessel (원통형 복합재료 압력 용기의 기계적 물성 평가를 위한 세그먼트 형 링 버스트 시험 방법 분석)

  • Kim, Woe Tae;Kim, Seong Soo
    • Composites Research
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    • v.34 no.4
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    • pp.257-263
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    • 2021
  • Composite materials have been widely applied for fabricating pressure vessels used for storing gaseous and liquid fuel because of their high specific stiffness and specific strength. Accordingly, the accurate measurement of their mechanical property, particularly the burst pressure or fracture strain, is essential prior to the commercial release. However, verification of the safety of composite pressure vessels using conventional test methods poses some limitations because it may lead to the deformation of the load transferring media or provoke an additional energy loss that cannot be ignored. Therefore, in this study, the segment-type ring burst test device was designed considering the theoretical load transferring ratio and applicable displacement of the vertical column. Moreover, to verifying the uniform distribution of pressure of the segment type ring burst test device, the hoop stress and strain distribution of ring specimens were compared with that of the hydraulic pressure test method via FEM. To conduct a simulation of the fracture behavior of the composite pressure vessel, a Hashin failure criterion was applied to the ring specimen. Furthermore, the fracture strain was also measured from the experiment and compared with that of the result from the FEM.

Fatigue Life Prediction of CFRP using Fatigue Progressive Damage Model (피로누적손상을 이용한 직조 CFRP의 피로수명 예측)

  • Jang, Jae-Wook;Cho, Je-Hyoung;Oh, Dong-Jin;Kim, Myung-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.52 no.3
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    • pp.248-254
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    • 2015
  • The strength and fatigue life of Satin and Twill-woven CF/epoxy composite(CFRP) have been investigated. Damage mechanism fatigue method has been used to assess fatigue damage accumulation. It is based on measured residual stiffness and residual strength of carbon-fiber reinforced plastic(CFRP) laminates under cyclic loading. Fatigue damage evolution in composite laminates and predict fatigue life of the laminates were simulated by finite element analysis(FEA) method. The stress analysis was carried out in MSC patran/Nastran. A modified Hashin's failure criterion di rmfjapplied to predict the failure of the experimental data of fatigue life but a Ye-delamination criterion was ignored because of 2D modeling. Almost linear stiffness and strength degradation were observed during most of the fatigue process. These stress distribution data were adopted in the simulation to simulate fatigue behavior and estimate life of the laminates. From the results, the predicted fatigue life is more conservatively estimated than the experimental results.

A Study on the Damage of CFRP Laminated Composites Under Out-of-Plane Load (횡방향 하중을 받는 CFRF 적층복합재의 내부손상에 관한 연구)

  • Kim, Moon-Saeng;Park, Seung-Bum;Oh, Deug-Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.11
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    • pp.98-109
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    • 1995
  • An investigation was performed to study the inner damage of laminated composite plates subjected to out-of-plane load. During the investigation, inpact velocity and equivalent static load relationship was derived. Reddy's higher-order shear deformation theory(HSDT) and Hashin's failure criteria were used to determine inner stresses and damaged area. And impact testing was carried out on laminated composite plates by air gun type impact testing machine. The CFRP specimens were composed of [ .+-. 45 .deg. ]$_{4}$and [ .+-. 45 .deg. /0 .deg. /90 .deg. ]$_{2}$ stacking sequences with 0.75$^{t}$ * 26$^{w}$ * 100$^{l}$ (mm) dimension. After impact testing. As a result, a relationship holds between damaged area and impact energy, and a matrix cracking was caused by the interlaminar shear stress in the middle ply and was caused by the inplane transverse stress in the bottom ply.

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Numerical analysis of stress wave of projectile impact composite laminate

  • Zhangxin Guo;Weijing Niu;Junjie Cui;Gin Boay Chai;Yongcun Li;Xiaodong Wu
    • Structural Engineering and Mechanics
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    • v.87 no.2
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    • pp.107-116
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    • 2023
  • The three-dimensional Hashin criterion and user subroutine VUMAT were used to simulate the damage in the composite layer, and the secondary stress criterion was used to simulate the interlayer failure of the cohesive element of the bonding layer and the propagation characteristics under the layer. The results showed that when the shear stress wave (shear wave) propagates on the surface of the laminate, the stress wave attenuation along the fiber strength direction is small, and thus producing a large stress profile. When the compressive stress wave (longitudinal wave) is transmitted between the layers, it is reflected immediately instead of being transmitted immediately. This phenomenon occurs only when the energy has accumulated to a certain degree between the layers. The transmission of longitudinal waves is related to the thickness and the layer orientation. Along the symmetry across the thickness direction, the greater is the stress amplitude along the layer direction. Based on the detailed investigation on the impact on various laminated composites carried out in this paper, the propagation characteristics of stress waves, the damage and the destruction of laminates can be explained from the perspective of stress waves and a reasonable layering sequence of the composite can be designed against damage and failure from low velocity impact.

Investigation on low velocity impact on a foam core composite sandwich panel

  • Xie, Zonghong;Yan, Qun;Li, Xiang
    • Steel and Composite Structures
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    • v.17 no.2
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    • pp.159-172
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    • 2014
  • A finite element model with the consideration of damage initiation and evolution has been developed for the analysis of the dynamic response of a composite sandwich panel subject to low velocity impact. Typical damage modes including fiber breakage, matrix crushing and cracking, delamination and core crushing are considered in this model. Strain-based Hashin failure criteria with stiffness degradation mechanism are used in predicting the initiation and evolution of intra-laminar damage modes by self-developed VUMAT subroutine. Zero-thickness cohesive elements are adopted along the interface regions between the facesheets and the foam core to simulate the initiation and propagation of delamination. A crushable foam core model with volumetric hardening rule is used to simulate the mechanical behavior of foam core material at the plastic state. The time history curves of contact force and the core collapse area are obtained. They all show a good correlation with the experimental data.

Buckling and post-buckling behaviors of 1/3 composite cylindrical shell with an opening

  • Ma, Yihao;Cheng, Xiaoquan;Wang, Zhaodi;Guo, Xin;Zhang, Jie;Xu, Yahong
    • Steel and Composite Structures
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    • v.27 no.5
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    • pp.555-566
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    • 2018
  • A 1/3 composite cylindrical shell with a central rectangular opening was axially compressed experimentally, and its critical buckling load and displacement, and strains were measured. A finite element model (FEM) of the shell with Hashin failure criteria was established to analyze its buckling and post-buckling behaviors by nonlinear Newton-Raphson method. The geometric imperfection sensitivity and the effect of side supported conditions of the shell were investigated. It was found that the Newton-Raphson method can be used to analyze the buckling and post-buckling behaviors of the shell. The shell is not sensitive to initial geometric imperfection. And the support design of the shell by side stiffeners is a good way to obtain the critical buckling load and simplify the experimental fixture.