Deformation and Failure Behavior of Woven Composite Laminates

1994 ◽  
Vol 116 (2) ◽  
pp. 222-232 ◽  
Author(s):  
M. Karayaka ◽  
P. Kurath
Keyword(s):  
Composite Laminates ◽  
Failure Mechanisms ◽  
Elastic Stiffness ◽  
Experimental Program ◽  
Internal Stresses ◽  
Failure Behavior ◽  
Deformation Model ◽  
Deformation And Failure ◽  
Linear Elastic ◽  
Proposed Model

Conceptually, fabric composites have some structural advantages over conventional laminates. However, deformation and failure analyses become more complex with the additional anisotropy introduced by the weaving geometry. A micromechanistic deformation model, that could realistically be incorporated into structural finite element codes, is proposed where loading direction and weave parameters are allowed to vary. Comparisons are made to previous models and experimental results for woven materials, indicating that the proposed model provides improved estimates for the linear elastic stiffness. The model further provides predictions for internal stresses in the longitudinal, transverse, and interlace regions of the woven laminate which qualitatively correspond to the experimentally observed failure mechanisms. The experimental program investigates deformations behavior and failure mechanisms of 5-harness 0/90 weave Graphite/Epoxy laminates under tension, compression, and 3-point and 4-point bending loading. Under these conditions the woven laminates exhibit orientation dependent mechanical properties and strength.

Deformation and failure behavior of hybrid composite laminates made of Glass Epoxy and woven Kevlar Epoxy

2020 ◽  
Author(s):  
Zeno Michael ◽  
Irfan Mahisham ◽  
Muhammad Farid Mahadi ◽  
Asyraf Naim Mohd Amin ◽  
Syed Irsyad Hilmi Syed Ahmad ◽  
...  
Keyword(s):  
Hybrid Composite ◽  
Composite Laminates ◽  
Failure Behavior ◽  
Deformation And Failure

Notch Effects in Tensile Behavior of AM60 Magnesium Alloys

2006 ◽  
Vol 312 ◽  
pp. 59-64 ◽  
Author(s):  
Cheng Yan ◽  
W. Ma ◽  
V. Burg ◽  
Yiu Wing Mai ◽  
M.G.D. Geers
Keyword(s):  
Magnesium Alloy ◽  
Failure Mechanisms ◽  
Stress Triaxiality ◽  
Tensile Behavior ◽  
Failure Behavior ◽  
Finite Element Analyses ◽  
Deformation And Failure ◽  
Ductile Tearing ◽  
Notched Specimens ◽  
Failure Point

The deformation and failure behavior of an AM60 magnesium alloy was investigated using tensile test on circumferentially notched specimens with different notch radii. The strain and stress triaxiality corresponding to the failure point were evaluated using both analytical and finite element analyses. Combining with systematical observations of the fracture surfaces, it is concluded that deformation and failure of AM60 magnesium alloy are notch (constraint) sensitive. The failure mechanisms change from ductile tearing to quasi cleavage with the increase of constraint.

Finite Element Modeling of a Mechanically Stabilized Earth Trial Wall

2021 ◽  
pp. 036119812110164
Author(s):  
Andrew Lees ◽  
Michael Dobie
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Retaining Wall ◽  
Back Analysis ◽  
Soil Parameters ◽  
Failure Behavior ◽  
Valuable Insight ◽  
Deformation And Failure ◽  
First Case ◽  
Soil Shear Strength

Polymer geogrid reinforced soil retaining walls have become commonplace, with routine design generally carried out by limiting equilibrium methods. Finite element analysis (FEA) is becoming more widely used to assess the likely deformation behavior of these structures, although in many cases such analyses over-predict deformation compared with monitored structures. Back-analysis of unit tests and instrumented walls improves the techniques and models used in FEA to represent the soil fill, reinforcement and composite behavior caused by the stabilization effect of the geogrid apertures on the soil particles. This composite behavior is most representatively modeled as enhanced soil shear strength. The back-analysis of two test cases provides valuable insight into the benefits of this approach. In the first case, a unit cell was set up such that one side could yield thereby reaching the active earth pressure state. Using FEA a test without geogrid was modeled to help establish appropriate soil parameters. These parameters were then used to back-analyze a test with geogrid present. Simply using the tensile properties of the geogrid over-predicted the yield pressure but using an enhanced soil shear strength gave a satisfactory comparison with the measured result. In the second case a trial retaining wall was back-analyzed to investigate both deformation and failure, the failure induced by cutting the geogrid after construction using heated wires. The closest fit to the actual deformation and failure behavior was provided by using enhanced fill shear strength.

scholarly journals Evaluation of Interlaminar Stresses in Composite Laminates with a Bolt-Filled Hole Using a Linear Elastic Traction-Separation Description

2017 ◽  
Vol 7 (1) ◽  
pp. 93
Author(s):  
Yong Cao ◽  
Yunwen Feng ◽  
Xiaofeng Xue ◽  
Wenzhi Wang ◽  
Liang Bai
Keyword(s):  
Composite Laminates ◽  
Interlaminar Stresses ◽  
Linear Elastic

Deformation and Failure Mechanisms of Austenitic Piping Under the Influence of Oxyhydrogen Reactions

2016 ◽  
Author(s):  
Stefan Offermanns ◽  
Stefan Weihe
Keyword(s):  
Failure Mechanisms ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Material Behavior ◽  
Inert Gas ◽  
Materials Testing ◽  
Failure Model ◽  
Adiabatic Shear Bands ◽  
Deformation And Failure ◽  
Gas Component

The present paper deals with the deformation and failure mechanisms of austenitic piping under the influence of oxyhydrogen reactions for the safety evaluation of incident scenarios in technical installations based on previous work of the author [1–5]. For the characterization of the processes, detonation tests performed at the Materials Testing Institute University of Stuttgart (MPA Stuttgart) have been used. The aim of these experiments was to study the detonation processes in head spray cooling piping of boiling water reactors. The experiments were performed on austenitic pipes with an outer diameter of O. D. = 114.3 mm and various wall thicknesses. Oxyhydrogen was used in its stoichiometric ratio of 2H2+O2 mixed with various amounts of an inert gas component. These tests have shown that less amounts of reactive gas may result in a stronger reaction of the pipe structure. This observation is attributed to the influence of the so-called overdriven detonation. Depending on the ratio of oxyhydrogen to the inert gas component and the pipe-wall thickness, adiabatic shear bands can occur in the piping structure. Adiabatic shear bands are very narrow zones with intense localized shear deformations due to the conversion of a significant portion of strain energy into heat. In order to describe this phenomenon numerically, a strain-based failure model was used which can reflect material damage over a wide range of different stress states. However, it has shown that damage of the studied material depends significantly on the Lode angle. Furthermore, no clear dependence of the failure limit on the loading rate has been found for the studied material. For the constitutive description of the material behavior under the occurring loading rates and temperatures suitable material models were selected and the required parameters have been evaluated experimentally and verified by numerical methods. With the aid of this constitutive description of the material behavior and the failure model numerical simulations of the detonation tests were carried out.

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