Tensile Fracture of Drawn Copper and Mild Steel

1982 ◽  
Vol 104 (1) ◽  
pp. 91-96 ◽  
Author(s):  
E. G. Thomsen

Annealed OFHC copper and SAE 1018 steel were reduced by multipass drawing from diameters of 25.4 mm (and smaller) to 11.8 mm. A comparison was made of the experimental draw stresses and those calculated by Sachs’ and Avitzur’s equations and fair agreement exists. The drawn bars were subsequently reduced in diameter by 10 percent in order to provide gage sections and then were pulled in tension to fracture. It was found that in multipass draws some work softening occurs. The oxygen-free copper showed indications that fracture was initiated at the center of the specimen. The internal fracture grew to the near shape of a sphere and separation did not occur until the load had almost decreased to zero. The mild steel apparently also fractured in the center, but complete separation took place immediately after the tensile stress reached its maximum. The fracture theories of Latham and Cockcroft, as well as that of Chen and Kobayashi, were examined and it was found that fair agreement existed. It was also found that for these particular tests, the maximum tensile stress criterion gave more convincing results.

Author(s):  
Victor Brizmer ◽  
Yuri Kligerman ◽  
Izhak Etsion

Failure inception of a deformable sphere loaded by a contacting rigid flat is analyzed separately for perfect slip and for full stick conditions and various material properties of the sphere. Ductile yielding and brittle failure inception of the sphere is identified by the critical interference and associated normal loading as well as the location of the first yield or failure occurrence. The analysis is based on the analytical Hertz solution for frictionless slip condition and on a numerical solution for stick condition. Failure inception is determined by using either the von Mises criterion of plastic yield or the maximum tensile stress criterion of brittle failure.


2011 ◽  
Vol 243-249 ◽  
pp. 4569-4575
Author(s):  
Yao Ying Huang ◽  
Hong Zheng

Suppose there is time course during the cracking and deforming process, the tensile cracking of rock-concrete materials was analyzed by means of elasto-viscoplastic model and its calculation steps were illustrated as well in this paper. The expression of function Φ in elasto-viscoplastic theory was studied; what’s more, it was comparatively analyzed the tensile cracking of rock-concrete materials by elasto-viscoplastic model and the maximum tensile stress criterion respectively. There are some differences comparing with the study of plastic yield by elasto-viscoplastic model, when analyzing the tensile cracking of rock-concrete materials on the basis of elasto-viscoplastic model, the function Φ should be the stress or stress formula of the direction where the principal stress firstly reaches the tensile strength; it is proved by the example analysis that it is feasible to study the tensile cracking of rock-concrete materials by elasto-viscoplastic model and there is no iteration stability issues.


2021 ◽  
Vol 29 (3) ◽  
pp. 67-74
Author(s):  
E. Baesu ◽  
DM. Iliescu ◽  
BV. Radoiu ◽  
S. Halichidis

Abstract Bone is a complex material that can be regarded as an anisotropic elastic composite material. The problem of crack propagation in human bone is analyzed by using a generalization of the maximum tensile stress criterion (MTS). The results concern the critical stress for crack propagation and the direction of the crack path in Iliac bone.


2006 ◽  
Vol 512 ◽  
pp. 55-60 ◽  
Author(s):  
Mao Qiu Wang ◽  
Eiji Akiyama ◽  
Kaneaki Tsuzaki

We examine the hydrogen embrittlement susceptibility of a high-strength AISI 4135 steel by means of a slow strain-rate test (SSRT) using notched round bar specimens. Hydrogen was introduced into the specimens by electrochemical charging and its content was measured by thermal desorption spectrometry (TDS). It was found that the maximum tensile stress decreased in a power law manner with increasing diffusible hydrogen content. Finite element method (FEM) calculations demonstrated that the peak value of the maximum principal stress and the peak value of the locally accumulated hydrogen concentration at the maximum tensile stress were in good agreement with one power law relationship for the specimens with different stress concentration factors.


Author(s):  
Ajay Garg

Abstract In high pressure applications, rectangular blocks of steel are used instead of cylinders as pressure vessels. Bores are drilled in these blocks for fluid flow. Intersecting bores with axes normal to each other and of almost equal diameters, produce stresses which can be many times higher than the internal pressure. Experimental results for the magnitude of maximum tensile stress along the intersection contour were available. A parametric finite element model simulated the experimental set up, followed by correlation between finite element analysis and experimental results. Finally, empirical methods are applied to generate models for the maximum tensile stress σ11 at cross bores of open and close ended blocks. Results from finite element analysis and empirical methods are further matched. Design optimization of cross bores is discussed.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5294
Author(s):  
Bangyi Liu ◽  
Yang Zhou ◽  
Linhao Gu ◽  
Xiaoming Huang

Uneven support as result of voids beneath concrete slabs can lead to high tensile stresses at the corner of the slab and eventually cause many forms of damage, such as cracking or faulting. Three-dimensional (3D) finite element models of the concrete pavement with void are presented. Mesh convergence analysis was used to determine the element type and mesh size in the model. The accuracy of the model is verified by comparing with the calculation results of the code design standards in China. The reliability of the model is verified by field measurement. The analysis shows that the stresses are more affected at the corner of the slab than at the edge. Impact of void size and void depth at the slab corner on the slab stress are similar, which result in the change of the position of the maximum tensile stress. The maximum tensile stresses do not increase with the increase in the void size for relatively small void size. The maximum tensile stress increases rapidly with the enlargement in the void size when the size is ≥0.4 m. The increments of maximum tensile stress can reach 183.7% when the void size is 1.0 m. The increase in slab thickness can effectively reduce maximum tensile stress. A function is established to calculate the maximum tensile stress of the concrete slab. The function takes into account the void size, the slab thickness and the vehicle load. The reliability of the function was verified by comparing the error between the calculated and simulated results.


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