Failure Inception of a Spherical Contact Under Slip and Stick Conditions for Various Material Properties

2005 ◽  
Author(s):  
Victor Brizmer ◽  
Yuri Kligerman ◽  
Izhak Etsion
Keyword(s):  
Tensile Stress ◽  
Numerical Solution ◽  
Material Properties ◽  
Brittle Failure ◽  
Maximum Tensile Stress ◽  
Normal Loading ◽  
Stress Criterion ◽  
Plastic Yield ◽  
Von Mises ◽  
Maximum Tensile Stress Criterion

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.

Analysis of the Tensile Cracking of Rock-Concrete Materials Based on Elasto-Viscoplastic Model

2011 ◽  
Vol 243-249 ◽  
pp. 4569-4575
Author(s):  
Yao Ying Huang ◽  
Hong Zheng
Keyword(s):  
Tensile Strength ◽  
Tensile Stress ◽  
Time Course ◽  
Maximum Tensile Stress ◽  
Viscoplastic Model ◽  
Stress Criterion ◽  
Plastic Yield ◽  
Concrete Materials ◽  
Stability Issues ◽  
Maximum Tensile Stress Criterion

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.

Tensile Fracture of Drawn Copper and Mild Steel

1982 ◽  
Vol 104 (1) ◽  
pp. 91-96 ◽  
Author(s):  
E. G. Thomsen
Keyword(s):  
Tensile Stress ◽  
Mild Steel ◽  
Maximum Tensile Stress ◽  
Complete Separation ◽  
Fair Agreement ◽  
Tensile Fracture ◽  
Ofhc Copper ◽  
Stress Criterion ◽  
Maximum Tensile Stress Criterion ◽  
Internal Fracture

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.

Mechanics of Composite Layered Rough Medium in Contact

2013 ◽  
Vol 703 ◽  
pp. 200-203
Author(s):  
Shao Biao Cai ◽  
Yong Li Zhao
Keyword(s):  
Material Properties ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Normal Loading ◽  
Layered Coatings ◽  
Pressure Profiles ◽  
Tangential Traction ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Tangential Friction

This study presents a first attempt to develop a numerical three-dimensional multilayered (more than 2 composite layered coatings) elasticperfectly plastic rough solids model to investigate the contact behavior under combined normal loading and tangential traction. Contact analyses are performed to study the effects composite thin film layers. Local contact pressure profiles, von Mises stresses, and shear stresses as a function of material properties and applied normal and tangential friction loads are calculated.

Convective Heat Transfer Steady Thermal Stress in a Ceramic/FGM/Metal Composite EFBC Plate with Temperature-Dependent Material Properties

2009 ◽  
Vol 79-82 ◽  
pp. 1363-1366 ◽  
Author(s):  
Yang Jian Xu ◽  
Dai Hui Tu
Keyword(s):  
Thermal Stress ◽  
Tensile Stress ◽  
Compressive Stress ◽  
Material Properties ◽  
Composite Plate ◽  
Maximum Tensile Stress ◽  
Metal Composite ◽  
Ceramic Surface ◽  
Temperature Dependent ◽  
Maximum Compressive Stress

A NFE model is constructed to analyze the convective heat transfer steady thermal stress in a ceramic/FGM/metal composite EFBC plate with temperature-dependent material properties. Based on thermoelasticity theory, we derive the NFE basic equation of heat conduction of the plate. We present a Sinpson method for the solution of steady thermal stress formulas of the composite plate. Using FORTRAN language we design the calculation software. From numerical calculation, when , T0=300K, Ta=500K and Tb=1 650K, the stress distributions in the plate were obtained. The results are as follows. With the increase of the FGM gradient layer thickness, the stress distribution is more reasonable, and the largest tensile stress of the EFBC composite plate reduces by 59.6%. With the increase of M, the stress change increases obviously in metal and ceramic layers, and the thermal compressive stress on the ceramic surface reduces by 78.1%. With the increase of porosity, the change of stress at the bonding interfaces increases, and the thermal compressive stress on the surface of ceramics reaches the maximum, and the thermal tensile stress on the surface of metal reaches the maximum too. Compared with , when , the tensile stress on the metal surface reduces by 91.3%, and the maximum compressive stress on the surface of ceramics increases 4.55 times. Compared with the nongraded two-layered ceramic/metal composite plate, the thermal stress of ceramic/FGM/metal composite EFBC plate is very gentle, and the maximum tensile stress reduces by 62.94%. When we consider the temperature-dependent material properties, the stress in graded three-layered composite plate becomes small obviously, and the maximum tensile stress in the plate reduces by 36.74%, and the maximum compressive stress on the ceramic surface reduces by 31.4%. The model can effectively analyze the thermal stresses and effect factors in a ZrO2/FGM/Ti-6Al-4V composite plate. The results provide the foundations of theoretical calculation for the design and application of the composite plate.

On the consequences of T-stress in elastic brittle fracture

2006 ◽  
Vol 462 (2072) ◽  
pp. 2415-2437 ◽  
Author(s):  
D.J Smith ◽  
M.R Ayatollahi ◽  
M.J Pavier
Keyword(s):  
Brittle Fracture ◽  
Tensile Stress ◽  
Brittle Failure ◽  
Maximum Tensile Stress ◽  
Experimental Results ◽  
Mode I ◽  
Mode Ii ◽  
T Stress ◽  
Mode Ii Loading

By using a generalized maximum tensile stress (MTS) criterion to predict onset of brittle fracture, it is shown that the presence of T-stress can have a significant effect on mode I and mode II toughness. The most prominent influence of T-stress on toughness occurs for mode II conditions. However, earlier tests concentrated on near mode I and results were masked by scatter. New experiments, using combinations of mode II loading and T-stress, support conclusively the generalized MTS criterion. This criterion is shown to be very robust and applicable to predicting probability of brittle failure. The criterion is also relevant to other experimental results where combinations of mode II loading with high values of T-stress can lead to values of mode II toughness that are greater than mode I toughness.

scholarly journals Mixed Mode Crack Propagation in Iliac Bone

2021 ◽  
Vol 29 (3) ◽  
pp. 67-74
Author(s):  
E. Baesu ◽  
DM. Iliescu ◽  
BV. Radoiu ◽  
S. Halichidis
Keyword(s):  
Crack Propagation ◽  
Critical Stress ◽  
Mixed Mode ◽  
Crack Path ◽  
Maximum Tensile Stress ◽  
Iliac Bone ◽  
Stress Criterion ◽  
Elastic Composite ◽  
Anisotropic Elastic ◽  
Maximum Tensile Stress Criterion

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.

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