A Quick Computation of Factor of Safety for Biaxial Stress States

1998 ◽  
Vol 120 (4) ◽  
pp. 721-726
Author(s):  
K. Deb
Keyword(s):  
Factor Of Safety ◽  
Biaxial Stress ◽  
Principal Stresses ◽  
Design Charts ◽  
Failure Theory ◽  
Safe Stress ◽  
Design Activities ◽  
Stress States ◽  
Failure Theories

Determination of overall factor of safety of a design involves repeated calculation of factor of safety at critical points in the design. For a given stress state at a point, the factor of safety is calculated by first finding the principal stresses and then comparing them with the maximum safe stress that can be applied without causing failure of the material according to an appropriate failure theory. In this paper, we suggest quick and ready-to-use expressions and graphs for calculating factor of safety for biaxial stress states for a number of commonly-used failure theories. These graphs can be directly used as design charts for computing factor of safety in engineering design activities.

Light Side of Design: Professional Vector

2020 ◽  
pp. 23-33
Author(s):  
Elena A. Zaeva-Burdonskaya ◽  
Yuri V. Nazarov
Keyword(s):  
Professional Practice ◽  
Wide Spectrum ◽  
Scientific Basis ◽  
Design Culture ◽  
Interdisciplinary Nature ◽  
Educational Programmes ◽  
Design Activities ◽  
The Subject ◽  
Light Side

This article addresses one of the most actively developing types of design activities – light design. The article comprises quotes of the leading Russian and foreign light design specialists published over the previous five years, as well as the authors’ own conclusions. The thoughts quoted in the article are sometimes opposite to each other and reflect the wide spectrum of professional practice. They reflect the initial opinions of analysts and experts which are often diverging. All of the specialists point at the interdisciplinary nature of the new profession, which imposes additional load on a designer overloaded enough already by the scope and speed of the problems being solved nowadays. The discussion of the new profession of light designer initiated on the pages of professional publications is especially important in view of the development of professional standards and standards of design and architectural education, as well as creation of new educational programmes based on various approaches to the subject in technical and humanitarian institutions. The goal of this article is to introduce light design into the field of fully legitimate sections of design culture, to define the authentic scientific basis of the new creative profession, to initiate a foundation for self-determination of the new synthetic area, which materially affects the state of the profession as a whole and the life standards of a wide variety of consumers. In order to reach the set goal, a comparative and analytical method of study was selected, which allows studying the problem to a large extent and from all angles and finding the ways of overcoming the challenges emerging in the area of the new activity.

Determination of a Rubber-Like Material Model as an Inverse Problem

2011 ◽  
Vol 70 ◽  
pp. 225-230 ◽  
Author(s):  
Agnieszka Derewonko ◽  
Andrzej Kiczko
Keyword(s):  
Selection Process ◽  
Axial Stress ◽  
Constitutive Models ◽  
Material Model ◽  
Polyester Fabric ◽  
Point Of View ◽  
Air Cushion ◽  
Ill Conditioning ◽  
Stress States

The purpose of this paper is to describe the selection process of a rubber-like material model useful for simulation behaviour of an inflatable air cushion under multi-axial stress states. The air cushion is a part of a single segment of a pontoon bridge. The air cushion is constructed of a polyester fabric reinforced membrane such as Hypalon®. From a numerical point of view such a composite type poses a challenge since numerical ill-conditioning can occur due to stiffness differences between rubber and fabric. Due to the analysis of the large deformation dynamic response of the structure, the LS-Dyna code is used. Since LS-Dyna contains more than two-hundred constitutive models the inverse method is used to determine parameters characterizing the material on the base of results of the experimental test.

Design charts for reinforced concrete L-sections

1976 ◽  
Vol 3 (4) ◽  
pp. 479-483
Author(s):  
Maher K. Tadros
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Strength ◽  
Normal Force ◽  
Basic Assumptions ◽  
Design Charts ◽  
Strength Design

The object of this paper is to present charts for the ultimate strength design of L-sections subjected to combined normal force and bending. The method of derivation of these charts is briefly described. It is general and applicable to other odd-shaped sections. It also conforms to the basic assumptions adopted in the CSA Standard A 23.3-1973. The charts can be used either for the determination of the dimensions of the section or for the check of its capacity.

Application of Moire Methods to the Determination of Transient Stress and Strain Distributions

1962 ◽  
Vol 29 (1) ◽  
pp. 23-29 ◽  
Author(s):  
W. F. Riley ◽  
A. J. Durelli
Keyword(s):  
Strain Distribution ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Distribution Problem ◽  
Principal Stresses ◽  
Transient Stress ◽  
Optical Phenomenon ◽  
Moiré Effect ◽  
Fringe Patterns

When two arrays of lines are superimposed an optical phenomenon known as the moire effect is observed under certain conditions. This moire effect is used by the authors to determine the distribution of transient strains on the surface of two-dimensional bodies. The method can be used to solve completely the strain-distribution problem or it can be used in combination with photoelasticity to separate the principal stresses. The methods used in interpreting the moire fringe patterns and the techniques used to produce the patterns are described in the paper. Two applications are discussed.

scholarly journals Determination of the Paleostress Orientations and Magnitudes for Missan Structures, Southeastern Iraq

2018 ◽  
Vol 26 (10) ◽  
pp. 213-233
Author(s):  
Atheer Edan Khalil AL- Hachem ◽  
Mustafa Rasheed Salih Al – Obaidi
Keyword(s):  
Principal Stress ◽  
Graphical Methods ◽  
Principal Stresses ◽  
Unstable Region ◽  
Diagram Method ◽  
Stress Orientations

        The use of  Right dihedral method and Mohr diagram method allow determination of the paleostress orientation and its magnitude in Missan structures, Southeastern Iraq. The principal stress orientations and its magnitudes have been determined by the measure of the striation on the faults planes. The measurement of orientation of the principal stress was deduced by different graphical methods, the horizontal maximum principal stresses (σ1) magnitudes were (3600, 4360,4650, 4750 and 5700) bars, the horizontal  intermediate  principal stresses (σ2) magnitudes   were (1528, 1842,1962.5, 1998.5 and 2390.5) bars and the vertical minimum principal stresses (σ3) magnitudes were (544, 676,725, 753 and 919) bars. This study shows that area is located within the unstable region since the poles of measured faults lie in the area of reactivated faults in Mohr diagram.

Evaluation of Ductile/Brittle Failure Theory and Derivation of the Ductile/Brittle Transition Temperature

2015 ◽  
Vol 83 (2) ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Transition Temperature ◽  
Brittle Failure ◽  
Evaluation Process ◽  
Isotropic Materials ◽  
Brittle Transition ◽  
Failure Theory ◽  
Ductile Brittle Transition Temperature ◽  
Brittle Transition Temperature ◽  
Materials Failure

A recently developed ductile/brittle theory of materials failure is evaluated. The failure theory applies to all homogeneous and isotropic materials. The determination of the ductile/brittle transition is an integral and essential part of the failure theory. The evaluation process emphasizes and examines all aspects of the ductile versus the brittle nature of failure, including the ductile limit and the brittle limit of materials' types. The failure theory is proved to be extraordinarily versatile and comprehensive. It even allows derivation of the associated ductile/brittle transition temperature. This too applies to all homogeneous and isotropic materials and not just some subclass of materials' types. This evaluation program completes the development of the failure theory.

Design Charts for Symmetrical Ring Girders

1957 ◽  
Vol 24 (1) ◽  
pp. 144-147
Author(s):  
G. P. Fisher
Keyword(s):  
Energy Analysis ◽  
Bending Moment ◽  
Bending Moments ◽  
Bending Energy ◽  
Normal Loading ◽  
Critical Design ◽  
Design Charts ◽  
Ring Location

Abstract Charts, based on classical bending-energy analysis, are presented for the determination of critical design moments in symmetrical ring girders varying in shape from circular through round to sharp-cornered rings. The girders are subjected to uniform normal loading in the plane of the ring. Location and magnitude of all critical bending moments are given, from which the maximum bending moment is easily selected.

A Rapid Method for the Determination of Principal Stresses Across Sections of Symmetry From Photoelastic Data

1938 ◽  
Vol 5 (1) ◽  
pp. A24-A28
Author(s):  
M. M. Frocht
Keyword(s):  
Free Boundary ◽  
Rapid Method ◽  
Circular Hole ◽  
Characteristic Curve ◽  
Principal Stresses ◽  
Recent Improvement ◽  
Tangential Stresses ◽  
Circular Holes ◽  
Photoelastic Data

Abstract The author discusses: (a) Mesnager’s theorem of isoclinics, (b) the characteristic curve of tangential stresses across a section of symmetry, (c) a formula for the maximum tangential stresses for the case of a central circular hole between fields of pure tension, (d) the slope of the p curve at a point corresponding to a cupic point, (e) recent improvement in the determination of free boundary stresses, and (f) formulas for the position of cupic points for two cases. A new method for the determination of the principal stresses across sections of symmetry from photoelastic data is illustrated with three examples: (1) Bars in tension or compression with central circular holes, (2) grooved beams in bending, and (3) rings or disks with circular central holes subjected to two concentrated diametral loads.

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