Influence from the inclined angle of the indenter for determination of residual stress and strain fields by sharp indentation testing

2007 ◽  
Vol 184 (1-3) ◽  
pp. 372-378 ◽  
Author(s):  
Per-Lennart Larsson
Keyword(s):  
Residual Stress ◽  
Stress And Strain ◽  
Indentation Testing ◽  
Strain Fields ◽  
Sharp Indentation ◽  
Inclined Angle

Endochronic Analysis of Cyclic Elastoplastic Strain Fields in a Notched Plate

1983 ◽  
Vol 50 (4a) ◽  
pp. 789-794 ◽  
Author(s):  
K. C. Valanis ◽  
J. Fan
Keyword(s):  
Residual Stress ◽  
Numerical Scheme ◽  
External Loading ◽  
Stress And Strain ◽  
Elastoplastic Strain ◽  
Residual Stress Field ◽  
Progressive Change ◽  
Strain Fields ◽  
Cyclic Tension ◽  
Cyclic Elastoplastic Strain

In this paper we present an analytical cum-numerical scheme, based on endochronic plasticity and the finite element formalism. The scheme is used to calculate the stress and elastoplastic strain fields in a plate loaded cyclically in its own plane along its outer edges and bearing two symmetrically disposed edge notches. One most important result that stands out is that while the external loading conditions are symmetric and periodic, the histories of stress and strain at the notch tip are neither symmetric nor periodic in character. In cyclic tension ratcheting phenomena at the tip of the notches prevail and a progressive change of the residual stress field at the notch line is shown to occur.

Determination of Strain Rate Depended Stress and Strain Fields in PVD Coatings on Cemented Carbide Inserts during the Repetitive Impact Test

2020 ◽  
Vol 404 ◽  
pp. 45-52
Author(s):  
Antonios Bouzakis ◽  
Georgios Skordaris ◽  
Konstantinos Dionysios Bouzakis ◽  
Mehmet Gökhan Gökcen ◽  
Apostolos Boumpakis ◽  
...  
Keyword(s):  
Strain Rate ◽  
Cemented Carbide ◽  
Stress And Strain ◽  
Strain Fields ◽  
Rate Dependent ◽  
Impact Forces ◽  
Repetitive Impact ◽  
Carbide Inserts ◽  
Fatigue Endurance

Recently, stress, strain, strain-rate dependent curves for cemented carbide have become an established tool for evaluating the mechanical properties. In this paper, related strain-rate dependent data of a K05 insert were employed to define the developed stress and strain fields occurring in the compound coating-substrate at impact forces of various durations. In this way, the occurring maximum strains at various impact loads and times were analytically calculated. These maximum values and related fatigue endurance coating strain-rate dependent limits were consequently used to validate published coating fatigue critical impact forces associated with certain impact times.

The residual stress and strain solutions of autofrettaged pressure vessels with a cone and cylinder connection

1992 ◽  
Vol 27 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Y Liu ◽  
N J Shen
Keyword(s):  
Residual Stress ◽  
Pressure Vessels ◽  
Stress And Strain ◽  
The Finite Element Method ◽  
Strain Fields ◽  
Non Linear ◽  
Residual Strains ◽  
Residual Stresses And Strains ◽  
Linear Loading ◽  
Element Method

This paper presents analysis and experimental research on an autofrettaged pressure vessel with a cone and cylinder connection. Non-linear loading stresses and strains and the unloading residual stresses and strains are considered. The residual stress and strain fields are obtained by the non-linear axisymmetric boundary element method (BEM). The results of the BEM are verified by means of the finite element method (FEM) program ADINA and compared with autofrettaged high pressure experiments. It is concluded that the calculated residual strains are in reasonable agreement with those determined experimentally.

An Analysis of the Roles of J and Q in the Assessment of Fracture for Quasi-Statically Extending Cracks in Residual Stress Fields

2009 ◽  
Author(s):  
David W. Beardsmore ◽  
J. K. Sharples ◽  
C. J. Madew ◽  
M. Jackson
Keyword(s):  
Residual Stress ◽  
Fracture Mechanics ◽  
Stress Field ◽  
Crack Tip ◽  
Stress And Strain ◽  
Stationary Crack ◽  
Proportional Loading ◽  
Strain Fields ◽  
Elastic Plastic ◽  
Crack Tip Fields

It is well known that the crack tip stress and strain fields for a crack in an elastic-plastic body depend on the crack tip contour integral J, the Q-stress, and the elastic-plastic properties of the material. This dependence is the fundamental basis of conventional two-parameter J-Q fracture mechanics assessments. It is normally assumed that the crack is created in an unstressed body, or else is inserted concurrently into an existing non-zero stress and strain field such that the crack tip fields build up monotonically and dominate at the crack tip. In such cases, the crack may be regarded as stationary and the J-Q procedure is valid provided that care is taken to calculate J and Q properly when initial stress and/or strains exist. When a crack is introduced progressively and quasi-statically into a component, the location of the crack tip will move along a distinct path. If the component contains residual stress and this is of a significant size along the crack tip path, a re-distribution of the residual stress will occur as the crack tip moves. Specifically, the stress field ahead of the crack tip will unload as the crack tip advances so that non-proportional loading will occur behind the advancing crack tip. In elastic-plastic materials, a wake of plasticity will usually be deposited in the material behind the moving or growing crack tip. Similar effects will also occur when a stationary crack extends due to critical or sub-critical processes. The presence of a plastic wake alters the stress and strain fields at the crack tip so that they do not generally match the fields of a stationary crack. Moreover, J and Q may not describe the stress and strain fields, invalidating the use of the fracture mechanics procedure for such cases. In this paper, a Finite Element analysis of J and Q is carried out for a quasi-statically extending crack inserted in a strip of elastic-plastic material containing an initial residual stress field. Care is taken to model the crack tip conditions appropriately as the crack extends and J is determined using the JEDI post-processing program which can allow for the effects of initial plastic strains and non-proportional loading. An assessment is made of the crack tip field and the likelihood of further extension or fracture is made using local approach models. The analysis considers both cleavage and ductile fracture. The extent of the relationship between J and Q and the crack tip fields is established and the validity of the J-Q procedure to such cases is discussed. The paper considers whether the procedure is conservative when J and Q are determined from an analysis of a stationary crack of the same size inserted into the same initial field.

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