Computer programs stress analysis

The most recent developments in computational stmctural analysis are almost all based on the direct stiffness matrix method. As a result, piping stress computer programs such as SIMPLEX, ADLPIPE, NUPIPE, PIPESD, and CAESAR, to name a few, use the stiffness method. 

When required, combined with the use of computers, the finite element analysis (FEA) method can greatly enhanced the capability of the structural analyst to calculate displacement and stress-strain values in complicated structures subjected to arbitrary loading conditions. In its fundamental form, the FEA technique is limited to static, linear elastic analysis. However, there are advanced FEA computer programs that can treat highly nonlinear dynamic problems efficiently. 

A detailed account of the methods used for the stresses analysis of tube sheets is given by Jawad and Farr (1989), and Singh and Soler (1992). Singh and Soler give computer programs for the design of the principal types of tube-plate. 

This method is the simplest and is well-suited to implementation in computer programs or spreadsheets [9]. Various standard statistical criteria, e g. the correlation coefficient, r the standard error of the slope of the regression line, 5 or the standard error of the estimate of g(or) from t, s, are used to quantify the deviation of a set of experimental points from the calculated regression line through them [10]. The inadequacies of r as an indicator of fit have been stressed [4,11]. The use of 5 is preferable in that its value is dependent upon the range of t used in the analysis. 

M. Zako, T. Ttujikami, Development of Personal Computer Program of Stress Analysis for Composite Materials, Journal of the society of material science, 38, No.438, (1990)... 

At the beginning of the 1960s, Schiffman (1962) introduced a general solution to analyse stresses/deformations in a multi-layer system. The suggested equations required extensive calculations and effectively were never used extensively. However, the development of computing Schiffman s analysis for an -layer system constituted the base of many software programs for the determination of pavement stresses and strains. 

The determination of stresses, strains and displacements in a multi-layer system is conducted by computer programs using, typically, three methods (a) the multi-layered elastic analysis, (b) two-dimensional (2D) finite element analysis and (c) three-dimensional (3D) finite element analysis. 

Stress analysis is carried out by using a linear elastic model, such as the computer program CIRCLY (Mincad Systems 2009). 

At present only special programs are available which take into account the creep performance of statically loaded plastics. The usual method is to use a creep-adjusted apparent modulus of elasticity in a second cut structural analysis to determine whether there will be serious creep effects on the product which must be accounted for in the design. With increased sophistication of the computer programs available it will soon be possible to do a direct computer analysis of the creep effects on a plastics component. In fact, there is current work on programs that produce a time model of the plastics component under load that will show how the stresses affect shape and load capabilities with time. 

Ghista DN, Hamid MS (1977) Finite element. Stress analysis of the human left ventricle where irregular shape is developed from single plane cineangiogram. Computer programs in biomedicine 7 219-231... 

Laminate analysis is based upon the principle of strain compatibility, which means that the in-plane strains in neighbouring layers must be equal. The stresses required in each layer to produce a given strain are first calculated from the previously-computed elastic constants of the layer for the appropriate angle to the fibre direction, and then integrated over all layers. The results define the clastic constants of the whole laminate. Simple computer programs take the drudgery out of these calculations. 

FTIR Studies of Polymers For the most part, the techniques used in the measme-ment of FTIR are the same as those applied to conventional samples. Spectral features of a component in a polymer are isolated from the solvent bands and from aU other compounds present in the system. Analysis is carried out by computer programs. Figure 17.26 shows the spectrum of polystyrene with an IR microscope through a 10-pm aperture. We see that the baseline is flat even below 1000 cm . This is very important because the frequency range of the IR spectrum below 1300 cm especially that below 1000 cm , is known as the fingerprint region. Changes in frequency and intensity may be used to determine the microscopic characterization of the polymer to see if there exists any defect due to stress or the environment. 

Khki.s, II., "A Review uml livulualion ol Computer Programs Cor the Analysis of Stresses in Pressure Vessels," IVTfC HuUeiin No. 108, Welding Research Council, New York, September... 

A.210. This section should describe methods for design and analysis of systems and components, including design transients, computer programs used, experimental stress analysis, and any programmes for dynamic testing and analysis of the mechanical systems and components. Particular attention should be paid to items important to safety. 

Sangrey DA, Henkel DJ, Esrig MI (1969) The effective stress response of a saturated clay soil to repeated loading. Can Geotech J 6(3) 241-252 Schnabel PB, Lysmer J, Seed HB (1972) SHAKE a computer program for earthquake response analysis of horizontally layered sites. Report no EERC72-12, Earthquake Engineering Research Center, University of California, Berkeley... 

There are about 25 time domain analysis computer programs that are available globally, either commercially or through direct contact with the author(s). However, only a handful of these programs have a provision to perform an effective-stress analysis, including 2-D and 3-D programs which can be used for analysis of 1-D geometry. 

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