Pure Torsion—Application of Model of Characteristic Failure Cross Sections

SummaryA theory of primary failure of compression panels of integral construction with unflanged stiffeners is presented, involving rotation, or translation, or rotation and translation of the stiffeners with the corresponding distortion of the sheet without deformation of the cross sections in their own planes. The investigation shows that the failure may occur generally either by pure torsion of the stiffener with the associated lateral distortion of the sheet or by pure flexure in accordance with whichever mode yields a smaller stress. The theory is compared with the test results covering a fairly wide range of the dimensions involved. The theory is in complete agreement with the experiments. The accuracy of the result thus obtained indicates that the fillets at the junction of the skin and the stiffener are not important and their effects may safely be disregarded.

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Exact Solution for Pure Torsion of SMA Curved Bars With Application to Analyzing SMA Helical Springs

ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Volume 1 ◽

10.1115/smasis2011-5184 ◽

2011 ◽

Author(s):

Reza Mirzaeifar ◽

Reginald DesRoches ◽

Arash Yavari

Keyword(s):

Cross Sections ◽

Pure Shear ◽

Three Dimensional ◽

Closed Form Solution ◽

Form Solution ◽

Stress Distributions ◽

Pure Torsion ◽

Helical Springs ◽

Torsional Response ◽

The One

In this paper, the pure torsion of SMA curved bars with circular cross sections is studied analytically. First, a three-dimensional phenomenological macroscopic constitutive model for polycrystalline SMAs is reduced to the one-dimensional pure shear case and then a closed-form solution for torsional response of SMA curved bars in loading and unloading is obtained. The effect of a direct shear force in the cross section is also considered in the solution which enables the formulation for analyzing SMA helical springs. Several case studies are presented in order to investigate the accuracy of the proposed method in predicting the torsional response of SMA curved bars, the stress distributions, and analyzing SMA helical springs.

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Torsion of Cylindrical and Prismatic Bars in the Presence of Steady Creep

Journal of Applied Mechanics ◽

10.1115/1.4011747 ◽

1958 ◽

Vol 25 (2) ◽

pp. 214-218

Author(s):

S. A. Patel ◽

B. Venkatraman ◽

P. G. Hodge

Keyword(s):

Closed Form ◽

Lower Bounds ◽

Cross Sections ◽

Creep Behavior ◽

Upper And Lower Bounds ◽

Elastic Analysis ◽

Steady Creep ◽

Pure Torsion ◽

Closed Form Solutions ◽

Creep Problem

Abstract This paper is concerned with the steady creep behavior of cylindrical and prismatic bars in which the deformations are caused by pure torsion. The creep problem is first reduced to one in nonlinear elasticity by means of the elastic analog. The elastic analysis is then carried out by means of the principles of minimum energies. These principles yield upper and lower bounds on the angle of twist. Closed-form solutions also are presented for some cross sections.

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On the Elastoplastic Stress Concentration at Reentrant Corners of Thin-Walled Cross Sections Subjected to Pure Torsion

Journal of Applied Mechanics ◽

10.1115/1.3167168 ◽

1983 ◽

Vol 50 (4a) ◽

pp. 898-901

Author(s):

D. Durban

Keyword(s):

Stress Concentration ◽

Cross Sections ◽

Pure Torsion ◽

Elastoplastic Stress ◽

Thin Walled

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Analysis of STEM micrographs of thick objects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081395 ◽

1978 ◽

Vol 36 (2) ◽

pp. 106-107

Author(s):

S. Golladay

Keyword(s):

Inelastic Scattering ◽

Multiple Scattering ◽

Mass Distribution ◽

Cross Sections ◽

Phase Contrast ◽

Image Point ◽

Contrast Effects ◽

Total Cross Sections ◽

Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

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