Three dimensional interlaminar stress analysis at free edges of composite laminate

This paper is a personal account of the origin and development of the twinned-calcite strain gauge, its experimental verification, and its relationship to stress analysis. The method allows the calculation of the three-dimensional deviatoric strain tensor based on five or more twin sets. A minimum of about 25 twin sets should provide a reasonably accurate result for the magnitude and orientation of the strain tensor. The opposite-signed strain axis orientation is the most accurately located. Where one strain axis is appreciably different from the other two, that axis is generally within about 10° of the correct value. Experiments confirm a magnitude accuracy of 1% strain over the range of 1–12% axial shortening and that samples with more than 40% negative expected values imply multiple or rotational deformations. If two deformations are at a high angle to one another, the strain calculated from the positive and negative expected values separately provides a good estimate of both deformations. Most stress analysis techniques do not provide useful magnitudes, although most provide a good estimate of the principal strain axis directions. Stress analysis based on the number of twin sets per grain provides a better than order-of-magnitude approximation to the differential stress magnitude in a constant strain rate experiment.

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Three-dimensional overall stress analysis for double-coated structure with equal coating thickness

Mechanics of Materials ◽

10.1016/j.mechmat.2021.103861 ◽

2021 ◽

Vol 158 ◽

pp. 103861

Author(s):

Shou-Ming Shang ◽

Peng-Fei Hou ◽

Wen-Hua Zhang

Keyword(s):

Stress Analysis ◽

Coating Thickness ◽

Three Dimensional

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Evaluation of two CAD/CAM materials for Nayyar core and post-retained restorations: Three dimensional stress analysis

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2021.104381 ◽

2021 ◽

Vol 117 ◽

pp. 104381

Author(s):

Nuran Ulusoy ◽

Laden Gulec Alagoz

Keyword(s):

Stress Analysis ◽

Three Dimensional ◽

Cad Cam

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Progressive failure analysis of scarf-repaired composite laminate based on damage constitutive model

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420716666400 ◽

2016 ◽

Vol 233 (2) ◽

pp. 180-188 ◽

Cited By ~ 2

Author(s):

Qiuyi Shen ◽

Zhenghao Zhu ◽

Yi Liu

Keyword(s):

Finite Element ◽

Constitutive Model ◽

Composite Laminate ◽

Damage Mechanics ◽

Cohesive Zone Model ◽

Load Capacity ◽

Three Dimensional ◽

Zone Model ◽

State Variables ◽

Element Analysis

A three-dimensional finite element model for scarf-repaired composite laminate was established on continuum damage model to predict the load capacity under tensile loading. The mixed-mode cohesive zone model was adopted to the debonding behavior analysis of adhesive. Damage condition and failure of laminates and adhesive were subsequently addressed. A three-dimensional bilinear constitutive model was developed for composite materials based on damage mechanics and applied to damage evolution and loading capacity analyses by quantifying damage level through damage state variables. The numerical analyses were implemented with ABAQUS finite element analysis by coding the constitutive model into material subroutine VUMAT. Good agreement between the numerical and experimental results shows the accuracy and adaptability of the model.

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