摘要:

AbstractSome recent developments are presented on a unified approach to the static and transient dynamic geometrically nonlinear analysis of Mindlin plates with initial imperfections.

ISSN:0029-5981    

DOI:10.1002/nme.1620171202

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo explicit representation of aC1quintic interpolant over triangles are given. These representations are derived by generalization of Coons' methods and Bernstein‐Bézier methods, respective

ISSN:0029-5981    

DOI:10.1002/nme.1620171203

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe following work proposes the use of a special description‐language for producing input data of finite element programs. The programs now used require a detailed description of the structure to be analysed, and they require it in a form which is unfavourable to the user and which promotes errors. Therefore, a language was designed which allows a short and compact description of the structure. This description is then automatically transformed into the input data. In this paper, the design process and the characteristics of the language are presented. Some comments on its implementation, that is on the development of a special preprocessor, are made. As target system, the finite element program SAP IV has been chosen. Finally, we want to present an example of the improvements achieved by the use of this language and the SAP IV preprocessor, respectivel

ISSN:0029-5981    

DOI:10.1002/nme.1620171204

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo alternative hybrid‐stress‐based functionals are examined for the incremental elastic‐plastic static analysis of single layer plates. Material nonlinear effects are incorporated via the initial‐stress approach so that an equivalent nodal force vector is defined and the stiffness remains constant throughout the incremental loading. The alternative functionals differ in the incremental stress which is assumed to satisfy equilibrium; in the first, it is the actual stress increment, and in the second it is the elastic stress increment. Results are presented for two example problems, and comparisons of the alternative functionals and plausible iteration schemes are given. The effects of variation of pertinent solution parameters are also shown. A 4‐node hybrid‐stress plate element based on a Mindlin‐type displacement field is used for most cases; however, limited results are also presented using an 8‐node plate element, thus permitting comparisons of the relative efficiencies of t

ISSN:0029-5981    

DOI:10.1002/nme.1620171205

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe transient thermal analysis of large aerospace vehicles such as the space shuttle requires models with thousands of degrees‐of‐freedom. The design of thermal protection systems for such vehicles requires the repetitive thermal analysis of the vehicle and the calculation of sensitivities—derivatives of the transient response with respect to design parameters. When the number of design parameters is large, the cost of the sensitivity calculations may become prohibitive. The present work is concerned with reducing the computational cost and errors in sensitivity calculations with one of the simplest available methods—the finite difference approach. A technique for calculating simultaneously the nominal and perturbed solutions required for the finite difference derivative is proposed. An expression for the optimum value of the perturbation parameter is obtained which permits reducing the computational error. An insulated cylinder is used as an example which demonstrates that significant improvements in accuracy and efficiency may be o

ISSN:0029-5981    

DOI:10.1002/nme.1620171206

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe nonlinear elastic problem involving the indentation of a slightly compressible rubber‐like layer bonded to a rigid cylinder and indented by another rigid cylinder is analysed by the finite element method. Both the geometric and material nonlinearities are accounted for. The finite element formulation of the problem is based upon a variational principle recently proposed by Cescotto and Fonder, and is valid for both slightly compressible and incompressible materials. The results computed and presented graphically include the shape of the indented surface, the pressure distribution over the contact surface, and the stress distribution at the bond surface. For the same contact width, the results for the compressible material are found to differ significantly from those for the case when the rubber‐like layer is assumed to be incompressi

ISSN:0029-5981    

DOI:10.1002/nme.1620171207

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA square tensile sheet with symmetric edge cracks is analysed by the finite element method to demonstrate the accuracy obtained with polynomial elements when the mesh patterns are chosen on the basis of the element's interpolation functions. Numerical results are provided for the accuracy of the total strain energy, the stress intensity factor, and the numerical condition of the global stiffness matrix. The stress intensity factor is determined to within 1.0 per cent accuracy using quadratic (linear strain) triangular elements with only 138 degrees‐of‐free

ISSN:0029-5981    

DOI:10.1002/nme.1620171208

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractFor plate bending analysis, both discrete and non‐discrete mixed methods are presented by using spline functions in the Hellinger‐Reissner variational principle. Piecewise spline interpolation with local supports and overall spline interpolation with boundary knots are applied to each of two mixed functionals. The prescribed boundary conditions can be considered by multiple boundary knots. The convergence behaviour of the mixed methods presented is studied. Numerical examples show that a high degree of accuracy can be obtained due to continuous properties in the high derivatives of the employed shape functions. The proposed mixed methods are found to be very competitive with other numerical methods for plate bending probl

ISSN:0029-5981    

DOI:10.1002/nme.1620171209

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA numerical method of the Newton‐Raphson type is presented for elasto‐plastic analysis using the finite element method. The method is developed from Nadai's deformation theory and Hooke's law. Numerical examples are used to show that the method provides very rapid solution converge

ISSN:0029-5981    

DOI:10.1002/nme.1620171210

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620171211

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY