Progressive failure behavior of pile-reinforced clay slopes under surface load conditions

2013 ◽  
Vol 71 (12) ◽  
pp. 5007-5016 ◽  
Author(s):  
Li Ping Wang ◽  
Ga Zhang
Keyword(s):  
Progressive Failure ◽  
Failure Behavior ◽  
Surface Load ◽  
Reinforced Clay ◽  
Clay Slopes ◽  
Load Conditions

Dynamic Characterization and Modeling of Carbon Composite Ballistic Behavior

2016 ◽  
Author(s):  
Chian-Fong Yen ◽  
Robert Kaste ◽  
Jian Yu ◽  
Charles Chih-Tsai Chen ◽  
Nelson Carey
Keyword(s):  
Composite Material ◽  
Progressive Failure ◽  
Laminated Composite ◽  
Carbon Composite ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Material Behavior ◽  
Failure Behavior ◽  
Failure Model ◽  
Carbon Composite Material

Design of the new generation of aircraft is driven by the vastly increased cost of fuel and the resultant imperative for greater fuel efficiency. Carbon fiber composites have been used in aircraft structures to lower weight due to their superior stiffness and strength-to-weight properties. However, carbon composite material behavior under dynamic ballistic and blast loading conditions is relatively unknown. For aviation safety consideration, a computational constitutive model has been used to characterize the progressive failure behavior of carbon laminated composite plates subjected to ballistic impact conditions. Using a meso-mechanics approach, a laminated composite is represented by a collection of selected numbers of representative unidirectional layers with proper layup configurations. The damage progression in a unidirectional layer is assumed to be governed by the strain-rate dependent layer progressive failure model using the continuum damage mechanics approach. The composite failure model has been successfully implemented within LS-DYNA as a user-defined material subroutine. In this paper, the ballistic limit velocity (V50) was established for a series of laminates by ballistic impact testing. Correlation of the predicted and measured V50 values has been conducted to validate the accuracy of the ballistic modeling approach for the selected carbon composite material. The availability of this modeling tool will greatly facilitate the development of carbon composite structures with enhanced ballistic and blast survivability.

Progressive Failure Analysis of an Integral Composite Joint for Thrust Reverser Cascade

2019 ◽  
Vol 795 ◽  
pp. 325-332
Author(s):  
Ji Shen Yang ◽  
Hong Yu Qi ◽  
Xiao Guang Yang ◽  
Duo Qi Shi
Keyword(s):  
Carrying Capacity ◽  
Composite Structure ◽  
Progressive Failure ◽  
Damage Model ◽  
Research Work ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Composite Joint ◽  
Bending Load ◽  
Load Carrying

The research work in this paper is focused on studying the failure behavior of an integral π-shaped laminated composite structure subjected to a bending load. A progressive damage model based on the 3D Tsai-Wu failure criterion and a developed gradual degradation model was employed to simulate and assess the load-carrying capacity, the onset and propagation of damage, and the failure mechanisms. For this unique π-shaped composite structure, disbonding was found to be the dominant damage mode under bending load, and the approximate maximum load could be maintained for a brief time during the final failure due to the gradual loss nature of the load-carrying capacity. The extent of damage was found to be more serious on the side of Rib II compared to the other side.

scholarly journals Progressive Failure Analysis of Laminates with Embedded Wrinkle Defects Based on an Elastoplastic Damage Model

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2422
Author(s):  
Zhi Hua Ning ◽  
Guan Liang Huo ◽  
Ren Huai Liu ◽  
Wei Lin Wu ◽  
Jia Ming Xie
Keyword(s):  
Failure Analysis ◽  
Composite Laminates ◽  
High Efficiency ◽  
Progressive Failure ◽  
Golden Section ◽  
Damage Model ◽  
Failure Behavior ◽  
Progressive Failure Analysis ◽  
Out Of Plane ◽  
Elastoplastic Damage

Out-of-plane wrinkling has a significant influence on the mechanical performance of composite laminates. Numerical simulations were conducted to investigate the progressive failure behavior of fiber-reinforced composite laminates with out-of-plane wrinkle defects subjected to axial compression. To describe the material degradation, a three-dimensional elastoplastic damage model with four damage modes (i.e., fiber tensile failure, matrix failure, fiber kinking/splitting, and delamination) was developed based on the LaRC05 criterion. To improve the computational efficiency in searching for the fracture angle in the matrix failure analysis, a high-efficiency and robust modified algorithm that combines the golden section search method with an inverse interpolation based on an existing study is proposed. The elastoplastic damage model was implemented in the finite-element code Abaqus using a user-defined material subroutine in Abaqus/Explicit. The model was applied to the progressive failure analysis of IM7/8552 composite laminates with out-of-plane wrinkles subjected to axial compressive loading. The numerical results showed that the compressive strength prediction obtained by the elastoplastic damage model is more accurate than that derived with an elastic damage model. The present model can describe the nonlinearity of the laminate during the damage evolution and determine the correct damage locations, which are in good agreement with experimental observations. Furthermore, it was discovered that the plasticity effects should not be neglected in laminates with low wrinkle levels.

Failure Behaviors of 2D-Cf/Mg Composites Fabricated by Liquid-Solid Extrusion Following Vacuum Pressure Infiltration

2016 ◽  
Vol 256 ◽  
pp. 216-221
Author(s):  
Shao Lin Li ◽  
Le Hua Qi ◽  
Ji Ming Zhou ◽  
Ting Zhang ◽  
Kai Yuan Dong
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Ultimate Tensile Strength ◽  
Progressive Failure ◽  
Pyrolytic Carbon ◽  
Vacuum Pressure ◽  
Failure Behavior ◽  
Matrix Composites ◽  
Pressure Infiltration ◽  
Complete Failure

Liquid-solid extrusion following vacuum pressure infiltration technique (LSEVI), which integrates melting, pouring, infiltration, and liquid-solid forming under high infiltration pressure, is a promising technique for the fabrication of metal matrix composite. LSEVI technology combines the advantages of both squeeze casting and gas pressure infiltration method. In this study, 2D carbon fiber reinforced AZ91D matrix composites (2D-Cf/Mg composites) were fabricated by LSEVI. Pyrolytic carbon (PyC) coating was deposited on surface of T700 carbon fiber by chemically vapour deposited (CVD) before fabrication. SEM observation indicated that the composites were well fabricated by LSEVI. The ultimate tensile strength of 2D-Cf/Mg composites fabricated by LSEVI was 390-410 MPa. Two kinds of failure behavior were found during tensile test: abrupt failure and progressive failure. The abrupt failure was characterized by a complete failure after the ultimate tensile strength (UTS) was reached. The progressive failure was a unique failure behavior with gradual damage after the UTS. In the case of progressive failure, the remaining strength after the UTS was 79% of the UTS. There was a remaining strength of 200 MPa under the strain of 0.1. Fracture surface morphology indicated that the remaining strength was attributed to the gradual breakage of the fiber bundles.

Numerical Investigation of Post Buckling Strength and Failure Modes in Advanced Grid Stiffened Structure under Thermal-Mechanical Loads

2007 ◽  
Vol 334-335 ◽  
pp. 613-616
Author(s):  
Rui Xiang Bai ◽  
Bo Chen ◽  
Cheng Yan ◽  
Lin Ye ◽  
Ze Cheng Li ◽  
...  
Keyword(s):  
Failure Modes ◽  
Mechanical Load ◽  
Progressive Failure ◽  
Shear Deformation Theory ◽  
Failure Behavior ◽  
Linear Deformation ◽  
Failure Characteristics ◽  
Buckling Strength ◽  
Stiffened Structures ◽  
Post Buckling

This work investigated the post buckling strength and failure behavior of advanced grid stiffened structures (AGS) under thermal-mechanical load using a finite element method. Based on the first order shear deformation theory (FSDT), Von Karman non-linear deformation assumption, and a progressive failure criterion, the buckling, large deformation，local failure modes in the AGS were studied. The thermal effect was also analyzed. By some numerical examples, the failure characteristics of the AGS were discussed.

Tensile Deformation and Progressive Failure Behavior of Woven-Fabric GFRP Laminates at Cryogenic Temperatures

Aerospace ◽  
2004 ◽  
Author(s):  
Satoru Takano ◽  
Tomo Takeda ◽  
Yasuhide Shindo ◽  
Fumio Narita
Keyword(s):  
Finite Element ◽  
Tensile Deformation ◽  
Progressive Failure ◽  
Woven Fabric ◽  
Failure Behavior ◽  
Cryogenic Temperatures ◽  
Scale Analysis ◽  
Damage Development ◽  
Fabric Composite ◽  
Macro Scale

This paper focuses on understanding the deformation and progressive failure behavior of glass/epoxy plain weave fabric-reinforced laminates subjected to uniaxial tension load at cryogenic temperatures. Cryogenic tensile tests were conducted on the woven-fabric laminates, and the damage development during loading was characterized by AE (acoustic emission) measurements. A finite element methodology for progressive failure analysis of woven-fabric composite panels was also developed, and applied to simulate “knee” behavior in the stress-strain responses and damage behavior in the tensile test specimens. The effect of strain concentrations due to the fabric architecture on the failure strain of the material was considered by incorporating the SVF (strain variation factor) from meso-scale analysis of a woven-fabric composite unit into the macro-scale analysis of the specimens. A comparison was made between the finite element predictions and the experimental data, and the agreement is good.

Modeling and simulation of carbon composite ballistic and blast behavior

2019 ◽  
Vol 54 (4) ◽  
pp. 485-499
Author(s):  
Chian-Fong Yen ◽  
Bob Kaste ◽  
Charles Chih-Tsai Chen ◽  
Nelson Carey
Keyword(s):  
Composite Material ◽  
Progressive Failure ◽  
Laminated Composite ◽  
Blast Loading ◽  
Carbon Composite ◽  
Ballistic Impact ◽  
Failure Behavior ◽  
Loading Conditions ◽  
Failure Model ◽  
Carbon Composite Material

The design of the next generation of aeronautical vehicles is driven by the vastly increased cost of fuel and the resultant imperative for greater fuel efficiency. Carbon fiber composites have been used in aeronautical structures to lower weight due to their superior stiffness and strength-to-weight properties. However, carbon composite material behavior under dynamic ballistic impact and blast loading conditions is relatively unknown. For aviation safety consideration, a computational constitutive model has been used to characterize the progressive failure behavior of carbon laminated composite plates subjected to ballistic impact and blast loading conditions. Using a meso-mechanics approach, a laminated composite is represented by a collection of selected numbers of representative unidirectional layers with proper layup configurations. The damage progression in a unidirectional layer is assumed to be governed by the strain-rate-dependent layer progressive failure model using the continuum damage mechanics approach. The composite failure model has been successfully implemented within LS-DYNA® as a user-defined material subroutine. In this paper, the ballistic limit velocity (V50) was first established for a series of laminates by ballistic impact testing. Correlation of the predicted and measured V50 values has been conducted to validate the accuracy of the ballistic modeling approach for the selected carbon composite material. A series of close-in shock hole blast tests on carbon composite panels were then tested and simulated using the LS-DYNA® Arbitrary-Lagrangian-Eulerian (ALE) method integrated with the Army Research Laboratory (ARL) progressive failure composite model. The computational constitutive model has been validated to characterize the progressive failure behavior in carbon laminates subjected to close-in blast loading conditions with reasonable accuracy. The availability of this modeling tool will greatly facilitate the development of carbon composite structures with enhanced ballistic impact and blast survivability.

Influence of the Geometric Imperfection on the Buckling Behavior of Floating Platform Column Under Axial Load

2007 ◽  
Author(s):  
Tiago P. Estefen ◽  
Daniel S. Werneck ◽  
Segen F. Estefen
Keyword(s):  
Progressive Failure ◽  
Correlation Study ◽  
Gas Production ◽  
Small Scale ◽  
Failure Behavior ◽  
Floating Platform ◽  
Cross Sectional ◽  
Geometric Imperfection ◽  
Stiffened Panels ◽  
Buckling Behavior

The present work focuses on the design of the new generation of semi-submersible platforms for oil&gas production offshore that is based on column square cross-sectional area. The platform column is based on an arrangement of stiffened flat panels having their ultimate strength characterized by buckling under in-plane compressive loading. Distortions induced by fabrication have considerable influence on the buckling behavior and are discussed in order to provide design recommendations. The aim of the paper is to study a segment of the column structural arrangement between robust transverse frames to analyze the failure behavior of the stiffened panels. Previous research demonstrated the strong influence of both mode and magnitude of the geometric imperfection distribution, as well as the boundary conditions. Numerical and experimental simulations for small scale isolated panels are carried out in order to perform a correlation study to adjust the numerical model for further use in more complex numerical simulations of the structural failure of the column arrangement. The stiffened panels are analyzed to identify the buckling initiation on a particular panel and then the interaction between plates, longitudinal stiffeners and the robust transverse frames during the progressive failure of the whole column.

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