On determining temperature dependent interfacial shear properties and bulk residual stresses in fibrous composites

1990 ◽  
Vol 38 (12) ◽  
pp. 2425-2433 ◽  
Author(s):  
B.N Cox ◽  
M.S Dadkhah ◽  
M.R James ◽  
D.B Marshall ◽  
W.L Morris ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Interfacial Shear ◽  
Fibrous Composites ◽  
Temperature Dependent ◽  
Shear Properties

Thermomechanical Model of Spot Welding for Calculating Residual Stresses

2003 ◽  
Author(s):  
Lijun Xu ◽  
Jamil A. Khan
Keyword(s):  
Residual Stresses ◽  
Heat Generation ◽  
Spot Welding ◽  
Welding Process ◽  
Mechanical Analysis ◽  
Temperature Dependent ◽  
Thermomechanical Model ◽  
Faying Surface ◽  
Proposed Model ◽  
Electrode Interface

A comprehensive axisymmetric model of the coupled thermal-electrical-mechanical analysis predicting weld nugget development and residual stresses for the resistance spot welding process of Al-alloys is developed. The model estimates the heat generation at the faying surface, the workpiece-electrode interface, and the Joule heating of the workpiece and electrode. The phase change due to melting in the weld pool is considered. The contact area and its pressure distribution at both the faying surface and the electrode-workpiece interface are determined from a coupled thermal-mechanical model using a finite element method. The knowledge of the interface pressure provides accurate prediction of the interfacial heat generation. For the numerical model, temperature dependent thermal, electrical and mechanical properties are used. The proposed model can successfidly calculate the nugget diameter and thickness, and predict the residual stresses and the elastic-plastic deformation history. The calculated nugget shape and the deformation of sheets based on the model are compared with the experimental data. The computed residual stresses approach the distribution of experimental measurement of the residual stress.

Temperature dependent dynamic shear properties of CFRP

Composites ◽  
1983 ◽  
Vol 14 (2) ◽  
pp. 141-144 ◽  
Author(s):  
A.J. Barker ◽  
H. Vangerko
Keyword(s):  
Dynamic Shear ◽  
Temperature Dependent ◽  
Shear Properties

Finite-Element Simulation of Temperature Fields and Residual Stresses in Butt Welded Joints and Comparison With Experimental Measurements

2014 ◽  
Author(s):  
Enrico Armentani ◽  
Angela Pozzi ◽  
Raffaele Sepe
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Base Plate ◽  
Element Model ◽  
Temperature Fields ◽  
Structural Members ◽  
Temperature Dependent ◽  
Welding Temperature ◽  
Element Simulation ◽  
Surrounding Areas

Welding is used in fabrication of structures ranging from small components to large and important structures. One of the important problems associated with welded structures is development of residual stresses and deformations due to welding temperature. In fact when structures are manufactured by welding, a non-uniform temperature distribution is produced. This distribution initially causes a rapid thermal expansion followed by a thermal contraction in the weld and surrounding areas, thus generating inhomogeneous plastic deformation and residual stresses in the weldment when it is cooled. High residual stresses in regions close to the weld may promote brittle fracture, fatigue, or stress corrosion cracking. Meanwhile, distortion in base plate may reduce the buckling strength of structural members. Therefore estimating the magnitude and distribution of welding residual stresses and distortion are necessary for achieving the safest design. In the present work an elastic-plastic finite element model considering temperature dependent mechanical properties is used to evaluate residual stresses. In this study a parametric model is adopted and the elements birth and death are used in single-pass butt welded joint to simulate the weld filler variation with time. Then numerical results are compared with experimental data.

Generating Compressive Surface Residual Stresses Using Hydraulic Autofrettage Process With Heat Treatment

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Rajkumar Shufen ◽  
Uday S. Dixit
Keyword(s):  
Heat Treatment ◽  
Critical Temperature ◽  
Residual Stresses ◽  
Outer Wall ◽  
Temperature Dependent ◽  
Surface Residual Stresses ◽  
Lower Critical Temperature ◽  
Lower Temperature ◽  
Compressive Residual Stresses ◽  
Treatment Design

Abstract Recently, a method of inducing compressive residual stresses in the vicinity of the walls of a thermally autofrettaged cylinder was proposed. In the proposed method, the thermally autofrettaged cylinder was heated in such a manner that its outer wall attained a temperature more than the lower critical temperature and the inner wall was at a sufficiently lower temperature. When the cylinder was quenched, compressive residual stresses were induced in the vicinity of the cylinder walls. This article investigates the feasibility of the same procedure for a hydraulic-autofrettaged cylinder made of AISI 1080 steel. A finite element method (FEM)-based analysis is carried out using commercial package abaqus by incorporating microstructure and temperature-dependent material properties. The results indicate that the heat treatment design proposed for the thermally autofrettaged cylinder to induce compressive residual stresses at the outer wall can also be adapted for a hydraulic-autofrettaged cylinder. However, for cylinders subjected to high percentage of autofrettage, heating of the outer wall needs to be carried out well below the lower critical temperature. In fact, this is an advantage in terms of energy saving and can be implemented even for cylinders subjected to a low percentage of autofrettage.

Finite Element Analysis of Residual Stresses on Butt Welded Joints

2006 ◽  
Author(s):  
Enrico Armentani ◽  
Renato Esposito ◽  
Raffaele Sepe
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Fusion Zone ◽  
Welded Joints ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Of Fusion ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Welding Processes

Localized heating during welding, followed by rapid cooling, usually generates residual stresses in the weld and in the base metal. Residual stresses in welding processes give significant problems in the accurate manufacture of structures because those stresses heavily induce the formation of cracks in the fusion zone in high strength steels. Therefore, estimating the magnitude and distribution of welding residual stresses and characterizing the effects of certain welding conditions on the residual stresses are deemed necessary. In this work, residual stresses and distortions on butt welded joints are numerically evaluated by means of finite element method. The FE analysis allows to highlight and evaluate the stress field and his gradient around the fusion zone of welded joints, higher than any other located in the surrounding area. Temperature-dependent material properties, welding velocity, external mechanism constraints, technique of ‘element birth and death’ and latent heat of fusion are also taken into account. Some numerical results are compared with experimental data showing a very good correlation.

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