摘要:

AbstractA finite element model for the elastic–plastic analysis of plane frames is proposed. The formulation is based on the independent modelling of the displacement and plastic strain fields; the latter is modelled both over the cross‐section and along the element length as function of a finite number of parameters, which are considered as an extra set of independent variables, in addition to nodal displacements. Stress redistribution is allowed for over the cross‐section, but not over the element length, where the distribution of stress resultants (axial forces and bending moments) is imposed consistently with the assumed displacement model; stress redistribution in terms of stress resultants becomes possible only because of the finite number of redundancies introduced when assembling. It is shown that the model can be formulated in such a way that not only compatibility and elasticity, but also equilibrium (in the sense of beam theory), are fully complied with and only the plastic portion of the constitutive relationship is approximately fulfilled, even if, in principle, to any desired level of accuracy. The model produces accurate results, including a detailed representation of the spreading of plastic zones, with a fairly limited number of ele

ISSN:0029-5981    

DOI:10.1002/nme.1620201202

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA finite element method for contact problems in crack mechanics is developed on the basis of the penalty function method. The method is successfully applied to three important problems in fracture mechanics: a crack propagated from a pin hole, a two‐point supported specimen with an edge crack loaded by a stamp, and a thick plate with a through‐wall crack under bending fo

ISSN:0029-5981    

DOI:10.1002/nme.1620201203

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThree different numerical formulations of the confined compression creep of cartilage have been developed to study the feasibility of applying numerical methods to dynamically loaded joints in biomechanics. The accuracy, convergence and stability of these numerical methods are assessed. Extensions of the analysis to include joint lubrication and non‐uniform properties are discussed, and an example is given of cartilage under dynamic load conditions. It is found that with the amplitude of loading maintained constant, the deflection of cartilage reduces as the frequency of load application is increase

ISSN:0029-5981    

DOI:10.1002/nme.1620201204

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe transmission‐line‐matrix (t.l.m.) numerical analysis technique is used in this paper to evaluate resonant frequencies and field parameters of the generated modes in microwave ovens loaded with lossy process materials. Analysis is made for the variation of resonant frequencies with the loss factor of the loading material. Temperature rise profile through the load is predicted from the calculated results of field parameters of sustained modes. The demonstrated data are for the dimensional parameters of a rectangular cavity of a commercial microwave oven operating at the standard heating frequency 915

ISSN:0029-5981    

DOI:10.1002/nme.1620201205

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe present paper is concerned with the nonlinear finite solution of the postbuckling instability behaviour of thin shell structures in resonance regions of vibration. The development of reliable and efficient techniques for handling the dynamic postbuckling behaviour is emphasized. An illustrative solution associated with the postbuckling resonance response of thin shells is presented.

ISSN:0029-5981    

DOI:10.1002/nme.1620201206

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractAn isoparametric shell element has been developed capable of linear response to the imposed loads. The original formulation, which was written for static and dynamic analyses, was extended to embrace linear buckling problems. A variety of numerical examples were attempted in order to assess the adaptability of the element to different geometrical representations. Despite serious size limitations of the computer, the accuracy of the predicted buckling loads was found to be satisfactory.

ISSN:0029-5981    

DOI:10.1002/nme.1620201207

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA total Lagrangian finite element formulation for the geometrically nonlinear analysis (large displacement/large rotations) of shells is presented. Explicit expressions of all relevant finite element matrices are obtained by means of the definition of a local co‐ordinate system, based on the shell principal curvature directions, for the evaluation of strains and stresses. A series of examples of nonlinear analysis of shell and plate structures is give

ISSN:0029-5981    

DOI:10.1002/nme.1620201208

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA combined iterative method is formulated for the partial solution of the eigenproblemAx= λBxthat arises from the application of the finite element method. The method is a combination of the conjugate gradient (CG) method and the symmetric successive co‐ordinate overrelaxation (SSCOR) method. Both of these methods belong to the same family of iterative methods which retain their vectorial form and approach the solution by seeking stationary points of the Rayleigh quotient. The formulation consists in splitting a characteristic matrix into the sum of two matrices, one of which corresponds to the SSCOR matrix, and then accelerating the associated iteration using the CG. The behaviour of the method is illustrated for five test cases and comparisons are made with other iterative methods. The influence of the relaxation parameter ω on the computational efficiency of the methods is also stud

ISSN:0029-5981    

DOI:10.1002/nme.1620201209

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractPart 1 of this paper1presents a very general single step algorithm SSpjfor the numerical integration of first and second order time dependent differential equations. In Part 2 we present and discuss results of the accuracy and stability analysis for SS11, SS21, SS31, SS22 and SS32. There is also a detailed comparison of SS22 and the Newmark algorithm.

ISSN:0029-5981    

DOI:10.1002/nme.1620201210

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper is the final in a series of three in which we have discussed a finite element post‐processing technique. Here we shall deal with the questions of adaptive mesh selection and aposteriorierror estimation. Some numerical examples computed by the FEARS program will be used to illustrate the approaches take

ISSN:0029-5981    

DOI:10.1002/nme.1620201211

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY