Nonlinear Bending of a Stress Corrosion Specimen

1966 ◽  
Vol 88 (1) ◽  
pp. 31-36
Author(s):  
Paul E. Wilson ◽  
Edward E. Spier
Keyword(s):  
Stress Corrosion ◽  
Flexural Rigidity ◽  
Axial Loads ◽  
Postbuckling Behavior ◽  
Nonlinear Bending ◽  
Corrosion Studies ◽  
Plate Strip ◽  
Stress States ◽  
Center Section

This paper presents an analysis of the postbuckling behavior of an initially straight plate strip of variable flexural rigidity whose ends are subjected to opposing “axial” loads. Bending action takes place only in the center section of the strip, since the symmetric end portions are considered to be rigid. Pertinent postbuckling load-deflection curves are deduced by using the nonlinear bending theory of a plate strip, and the maximum stress is obtained as a function of the half-distance between the loaded ends. Numerical results are presented in nondimensional form, and the theoretical solution is shown to compare favorably with a major portion of the experimental stress and deflection data. Information given here has an important and direct application to the determination of bending stress states in the lateral faces of a wide class of tensile test coupons used in stress corrosion studies.

On Nonlinear Bending of a Plate Strip

1965 ◽  
Vol 87 (4) ◽  
pp. 406-412
Author(s):  
P. E. Wilson
Keyword(s):  
Stress Corrosion ◽  
Maximum Stress ◽  
Direct Application ◽  
Numerical Results ◽  
Theoretical Solution ◽  
Experimental Results ◽  
Nonlinear Bending ◽  
Plate Strip ◽  
Stress States

Ends of an initially straight plate strip are rotated 90 deg. Using nonlinear bending theory, the maximum stress is obtained as a function of the half-distance between the rotated ends of the strip. Numerical results are presented in nondimensional form, and the theoretical solution is shown to compare favorably with experimental results. Information given here has a direct application to stress states in a stress corrosion specimen.

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.

scholarly journals Large Deflection Model for Multiple, Inline, Interacting Cantilever Beams

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Austin Bebee ◽  
Christopher J. Stubbs ◽  
Daniel J. Robertson
Keyword(s):  
Mathematical Model ◽  
Flexural Rigidity ◽  
Cantilever Beams ◽  
Model Concept ◽  
Math Model ◽  
Rigid Body Model ◽  
High Throughput Phenotyping ◽  
Stalk Lodging ◽  
The Mathematical Model

Abstract Numerous natural and synthetic systems can be modeled as clusters of interacting cantilever beams. However, a closed-form mathematical model capable of representing the mechanics of multiple interacting cantilever beams undergoing large deflections has yet to be presented. In this work, a pioneering mathematical model of the force–deflection response of multiple, inline, interacting (i.e., contacting) cantilever beams is presented. The math model enables the determination of the force–deflection response of a system of interacting cantilever beams and is predicated upon the “Pseudo Rigid Body Model” concept. The model was validated through data triangulation experiments which included both physical and computational studies. An analysis of the mathematical model indicates it is most accurate with deflections less than 50 deg. In the future, the model may be used in high throughput phenotyping applications for investigating stalk lodging and estimating the flexural rigidity of crop stems. The model can also be used to gain intuition and aid in the design of synthetic systems composed of multiple cantilever beams.

scholarly journals Size optimization of shoulder filleted shafts with relief grooves for improving their fatigue life

2017 ◽  
Vol 37 (3) ◽  
pp. 85-91
Author(s):  
Juan Manuel González-Mendoza ◽  
Samuel Alcántara-Montes ◽  
José De Jesús Silva-Lomelí ◽  
Carlos De la Cruz-Alejo ◽  
Arturo Ocampo-Ramírez
Keyword(s):  
Fatigue Life ◽  
Stress Concentration ◽  
Scientific Literature ◽  
Optimization Algorithms ◽  
Size Optimization ◽  
Axial Loads ◽  
Maximum Value ◽  
Optimum Geometry

Although in scientific literature there are studies regarding the inclusion of relief grooves in order to diminish the amount of stress concentration in stepped shafts, the incorporation of optimization algorithms capable of parametrically determining their geometry remains unexplored. In this paper, an approach to the problem of size optimization of shoulder filleted shafts with relief grooves and subject to axial loads is presented. The objective of the optimization is to minimize the maximum value of stress at both, the root of the shoulder fillet, and the root of the groove, thus minimizing stress concentration and improving fatigue life of such elements. Under this methodology, different percentages of reduction of stress are achieved for the shafts with relief grooves, in comparison with the shafts without relief grooves. The novelty of this approach lies in the incorporation of an algorithm for the determination of the optimum geometry of the grooves.

Photoelast Method and Possible Applications of Mathematical Statistics in Prediction of Stress State of Structural Elements

2014 ◽  
Vol 611 ◽  
pp. 405-411 ◽  
Author(s):  
Oskar Ostertag ◽  
Eva Ostertagová ◽  
Peter Frankovský
Keyword(s):  
Stress State ◽  
Stress Concentration ◽  
Stress Field ◽  
Statistical Methods ◽  
Mathematical Statistics ◽  
Structural Elements ◽  
State Development ◽  
Stress States ◽  
Structural Parts

The presented article is dedicated to stress state development while assessing the concentration of stresses in samples with continuously changing notches. These samples represent connecting elements of structural parts. The stress states of selected samples were determined experimentally by means of reflection photoelasticity. This method is suitable mainly for determination of stress state in the whole area in question, predominantly though for the analysis of stress concentration and its gradient in the notched area. Within the method of reflection photoelasticity, a layer was used to analyse the stress field. When loaded, this layer exhibits the ability of temporal birefringence. One of the statistical methods was selected in order to predict the stress state of other samples with bigger notches.

Analytical modeling of masonry load-bearing walls

2003 ◽  
Vol 30 (5) ◽  
pp. 795-806 ◽  
Author(s):  
Yi Liu ◽  
J L Dawe
Keyword(s):  
Flexural Rigidity ◽  
Computer Application ◽  
Masonry Walls ◽  
Load Bearing ◽  
Analytical Technique ◽  
Reinforced Masonry ◽  
Material Stiffness ◽  
The Moment ◽  
Magnification Effect

An analytical technique was developed and encoded for computer application to study the behaviour of concrete masonry load-bearing walls under various loading conditions. Both geometrical and material nonlinearities to account for the moment magnification effect and the degradation of material stiffness are included in the development. Effects of vertical reinforcing steel, masonry tensile cracking, and compressive crushing are included directly in the moment–curvature relationship, which is used in the determination of element stiffnesses at successive load increments. A parametric study was conducted following verification of the analytical model by comparing results with experimental test data. Effective flexural rigidity (EIeff) values at failure were obtained analytically and compared with values suggested in the Canadian masonry code CSA-S304.1-M94. It was concluded that CSA-S304.1-M94 tends to underestimate EIeff values for reinforced walls and thus leads to a conservative design over a range of parameters. Based on approximately 500 computer model tests, a lower bound bilinear limit for the effective rigidity of reinforced masonry walls was established. This limit is believed to provide an accurate and realistic estimate of EIeff.Key words: walls, load bearing, masonry, analytical, nonlinear, rigidity, stress–strain, moment–curvature.

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