Determination of active members and zero-stress states for symmetric prestressed cable–strut structures

2020 ◽  
Vol 231 (9) ◽  
pp. 3607-3620
Author(s):  
Linzi Fan ◽  
Yue Sun ◽  
Weiyin Fan ◽  
Yao Chen ◽  
Jian Feng
2011 ◽  
Vol 70 ◽  
pp. 225-230 ◽  
Author(s):  
Agnieszka Derewonko ◽  
Andrzej Kiczko

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.


1966 ◽  
Vol 88 (1) ◽  
pp. 31-36
Author(s):  
Paul E. Wilson ◽  
Edward E. Spier

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.


2014 ◽  
Vol 611 ◽  
pp. 405-411 ◽  
Author(s):  
Oskar Ostertag ◽  
Eva Ostertagová ◽  
Peter Frankovský

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.


1998 ◽  
Vol 120 (4) ◽  
pp. 721-726
Author(s):  
K. Deb

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.


2015 ◽  
Vol 11 (1) ◽  
pp. 29-37
Author(s):  
Giang Nguyen

Abstract The paper deals with the determination of stress induced in spread foundation subsoil by Slovak Technical Standard STN 73 1001:2010 (STN) and Polish Standard PN-81/B-03020 (PN). While STN does not consider with stress state in subsoil just after carrying out excavation and the stress is determined from overloading only, PN considers with stress states after carrying out excavation and follows loading. Differences are also in determination of foundation stiffness and taking into account soil structural strength. It will be shown that different approaches make difference in the value of additional stress up to 18.6 %.


1991 ◽  
Vol 239 ◽  
Author(s):  
Ferdinando Auricchio ◽  
Mauro Ferrari

ABSTRACTA closed-form solution for a macroscopically homogeneous, fully anisotropie layer subject to non-uniform through-thickness eigenstrain is presented, and employed in determining the three-dimensional deformation and stress states of a thermally loaded ceramic film with microstructure-induced macroscopic anisotropy. The resultant stress field is compared with those that could be deduced by experimental determination of the curvature and the classical structural theories.


1988 ◽  
Vol 41 (2) ◽  
pp. 189 ◽  
Author(s):  
RA Winholtz ◽  
JB Cohen

The determination of residual stresses via X-ray diffraction is briefly reviewed, with particular emphasis on the triaxial stress state. A new method is proposed for determining the general stress tensor, which considerably reduces the variances of the stresses due to counting statistics and gradients. The procedure involves a generalised least-squares solution of strains measured at various tilts of the X-ray beam to the sample, and a new set of tilts is recommended to minimise these errors.


Author(s):  
E. K. Agakhanov ◽  
S. T. Khidirov ◽  
G. G. Gabibulaev

Objective. Determination of the stress state of a ground base with a trapezoidal cutoff from the action of own weight, according to the conditions of equivalence of effects, is reduced to determining the stress state from the external surface load distributed according to the hydrostatic law. Methods. The problem of determining the stresses in the structure foundations at any degree of areas development of a plastic strain of the soil has a strict mathematical formulation, and similarity criteria can be obtained using a simpler construct of similarity theory. The simulation is performed by using similarity criteria based on which the model is executed, the loading conditions are determined, and the transition from the values measured on the model to the corresponding values of the full-scale structure is carried out. Similarity criteria can be obtained either with the help of similarity theory or with the help of dimensional analysis. An even greater effect of increasing the self-weight of a model made of transparent optically sensitive material can be achieved using the immersion method in conjunction with the centrifugal modeling method. If necessary, the stresses in the model area are fixed using the "freeze" method. Result. Using the equations system of the mixed problem of the elasticity and plasticity theory, and the scale method, similarity criteria are established for modeling stresses in the foundations of buildings and structures. Limitations on the choice of similarity multipliers for loose soils, the possibility of using the method of centrifugal modeling, as well as features of modeling connected soils are noted. Conclusion. A necessary condition for the similarity of the stress states of loose homogeneous bases in nature and the model is the equality of the similarity multipliers of the geometric scale and the force factor. 


Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 445
Author(s):  
Ivana Poláková ◽  
Michal Zemko ◽  
Martin Rund ◽  
Ján Džugan

The aim of this study was to calibrate a material model with two fracture criteria that is available in the DEFORM software on DIN 34CrNiMo6. The purpose is to propose a type of simple test that will be sufficient for the determination of damage parameters. The influence of the quantity of mechanical tests on the accuracy of the fracture criterion was explored. This approach was validated using several tests and simulations of damage in a tube and a round bar. These tests are used in engineering applications for their ease of manufacturing and their strong ability to fracture. The prediction of the time and location of the failure was based on the parameters of the relevant damage model. Normalized Cockroft-Latham and Oyane criteria were explored. The validation involved comparing the results of numerical simulation against the test data. The accuracy of prediction of fracture for various stress states using the criteria was evaluated. Both fracture criteria showed good agreement in terms of the fracture locus, but the Oyane criterion proved more suitable for cases covering larger triaxiality ranges.


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