On the Use of Power Laws in Stress Analysis Beyond the Elastic Range

1947 ◽  
Vol 14 (4) ◽  
pp. A281-A284
Author(s):  
Alice Winzer ◽  
W. Prager
Keyword(s):  
Plastic Deformation ◽  
Shear Modulus ◽  
Stress Analysis ◽  
Power Laws ◽  
Shearing Stress ◽  
Great Caution ◽  
Elastic Range ◽  
Secant Shear Modulus

Abstract In a recent paper A. A. Ilyushin drew attention to the remarkable simplicity which the theory of plastic deformation assumes when the secant shear modulus is taken as a power of the octahedral shearing stress. In the present paper Ilyushin’s results are discussed in connection with a specific example and it is shown that great caution is indicated in the use of such power laws.

Computer Simulation of Plastic Deformation in Tial Alloys in the Presence of Chromium

2018 ◽  
Vol 386 ◽  
pp. 383-387 ◽  
Author(s):  
Anton Gnidenko
Keyword(s):  
Computer Simulation ◽  
Plastic Deformation ◽  
Shear Modulus ◽  
Titanium Aluminide ◽  
Shear Resistance ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Tial Alloys ◽  
Shear Rupture ◽  
Titanium Vacancy

Quantum-mechanical calculations were used to investigate shear rupture in intermetallic titanium aluminide (TiAl) alloys in the presence of vacancy or chromium dopant. The substitution of both Ti and Al atoms by Cr atoms in the γ-TiAl crystal lattice was considered. The simulation of shear was carried out in the (111) slip plane along two directions, namely the [110] and [11-2]. The decrease in the shear resistance of the defects present in the γ-TiAl lattice was estimated. It was shown that when chromium occupies a titanium vacancy, it can compensate for this defect by increasing the shear modulus for the {111} <110> slip system.

The Influence of the Fatigue Cycles Number on Material Hardness

2014 ◽  
Vol 658 ◽  
pp. 195-200
Author(s):  
Viorel Goanta
Keyword(s):  
Plastic Deformation ◽  
Indentation Load ◽  
The Other ◽  
Stress Cycle ◽  
Elastic Range ◽  
Maximum Value ◽  
Material Hardness ◽  
Stress Fatigue ◽  
Minimum Force ◽  
Maximum Minimum

In this paper we present the experimental results obtained after determining hardness on samples previously subjected to fatigue. Firstly, 6 identical samples have been subjected to stress fatigue in the elastic range a number of 105, 5∙105, 106, 2∙106, 3∙106 and 4∙106 cycles. For all samples we used the same form of stress cycle, respectively, sinusoidal, and the same values of maximum, minimum force and the amplitude of the cycle (50 kN, 30 kN and 10 kN). It is noted that the maximum value of the load was less than that at which samples fall within the plastic deformation. Therefore, the original loading of samples was performed in the elastic range. For each of the six samples determinations of levels of hardness were performed, with the value of indentation load of 10 kgf. Indentations were made on the samples, along the length of the calibration, at a distance of 10 mm one within the other. As it will be seen below, in the areas with the highest hardness were performed several indentations, in order to determine the highest hardness area, which, in our view, also presents the largest degree of plastic deformation.

Elasto-Plastic Contact Stress Analysis of Hardened Elements under Repeated Contact Loading

2019 ◽  
Vol 823 ◽  
pp. 91-96
Author(s):  
Chang Hung Kuo
Keyword(s):  
Plastic Deformation ◽  
Stress Analysis ◽  
Contact Stress ◽  
Surface Hardness ◽  
Hardened Layer ◽  
Rolling Contact ◽  
Plastic Behavior ◽  
Contact Loading ◽  
Cyclic Plastic ◽  
Elastic Plastic

An elastic-plastic contact stress analysis is presented to study cyclic plastic deformation of surface hardened rolling elements under repeated contacts. The rolling contact is simulated by a Hertz contact loading moving across an elastic-plastic half-space. An exponential model with hardness varying with depth is employed for the surface hardened components, and the Chaboche nonlinear hardening rule is used to model cyclic plastic behavior of contact elements. Numerical results show that the hardened layer can effectively reduce the plastic deformation near contact surface. The contact elements with sufficient surface hardness may reach elastic shakedown state under repeatedly rolling contact. As the hardened layer reaches a certain depth, e.g. two times of half contact length, however, the effects of case depth on plastic strain and residual stress become negligible after hundred contact cycles.

Stress Analysis of Laminated Glass under Uniform Lateral Pressure

2011 ◽  
Vol 418-420 ◽  
pp. 50-54
Author(s):  
Shi Hong Pang ◽  
Juan Rong Ma ◽  
Zhen Zhu Ma ◽  
Li Chuang Wang
Keyword(s):  
Finite Element ◽  
Shear Modulus ◽  
Finite Element Model ◽  
Stress Analysis ◽  
Lateral Pressure ◽  
Element Model ◽  
Maximum Principal Stress ◽  
Laminated Glass ◽  
Load Duration ◽  
Simulation Results

The shear modulus of PVB and SGP interlayer is analyzed. With the same conditions of load duration and temperature, the shear modulus of SGP interlayer is about fifteen times than that of PVB interlayer. A finite element model of laminated glass is established in this paper. The simulation results show that the maximum principal stress contours of PVB laminated glass change from a circular to a petal-shaped one and those of SGP laminated glass change form a quadrangular to a square-shaped one when the temperature rises from 20 degrees Celsius to 50 degrees Celsius.

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