摘要:

A systematic classification of the variational functional whose stationarity conditions (Euler equations) can be used alternately to solve for the various unknowns in a boundary-value problem in linear-shell theory is made. The application of these alternate variational principles to a finite-element assembly of a shell and thus, the development of the properties of an individual discrete element are studied in detail. A classification of the finite-element methods, formulated from the variational principles by systematically relaxing the continuity requirements at the interelement boundaries of adjoining discrete elements is made.

ISSN:0360-1218    

DOI:10.1080/03601217208905331

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

On the basis of a probabilistic fomulation of the fundamental theorems of “limit analysis,” a procedure is developed which allows, with a very limited amount of computing work, the determination of a domain containing the probability distribution curve of the collapse load factor of any structure that satisfies the usual conditions for validity of the limit analysis, but has randomly distributed limit strengths.

ISSN:0360-1218    

DOI:10.1080/03601217208905332

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

In recent years, a considerable amount of effort has been made on the part of structural engineers to model the excitation to structures as a random process and to analyze the structural response so that Structural behaviors under nondeterministic disturbances can be predicted with certain probability statements. However, much less work has been accomplished dealing with structures with a random property. This appears to be due to the fact that the governing equations of motion for structures with spatial statistical variation of material property involve stochastic parameters and are usually extremely difficult to solve. This paper introduces a Monte Carlo approach to solve structural problems of this kind and deals, as an example, with the stress-wave propagation through a random structure under impact loading. Through this is example, total compatibility of the proposed approach with the infinite element analysis, which is capable of taking into consideration the effects of irregular boundaries, nonlinear material properfies, and finite displacements, is demon- strated. Such generality is beyond the reach of analytical mcthods, but is required for problems of engineering importance. The complexity of the structure is limited only by the computing facilities available, and the accuracy of the sample statistics by the computational time required.

ISSN:0360-1218    

DOI:10.1080/03601217208905333

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The buckling loads of straight, simply supported columns, loaded by axial thrust are maximized, subject to the restriction that the available volume of structural material is specified. In addition, a constraint is placed upon the maximum allowable prebuckling stress. Analytic solutions are presented for a variety of different cross-sectional geometries.

ISSN:0360-1218    

DOI:10.1080/03601217208905334

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A general discussion of the behavior of the shallow circular arch is presented. It is shown that, irrespective of specific loading or boundary conditions, it is possible to arrive at general conclusions regarding buckling, postbuckling, and imperfection sensitivity. General methods of analysis are established which lead to the determination of points of bifurcation and of postbuckling paths under symmetric loads. Modifications accounting for antisymmetric load components are introduced, with special emphasis on their asymptotic and limit load effect.

ISSN:0360-1218    

DOI:10.1080/03601217208905335

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The concept of conjugate approximation functions is generalized to mixed formulations of linear boundary value problems. Biorthogonal basis functions are generated using two distinct finite-element models of the domain of a given function. Various special cases are considered. It is shown that four distinct models can be developed corresponding to a single linear operator. A comparison of the concepts of the hypercircle and conjugate approximation is given.

ISSN:0360-1218    

DOI:10.1080/03601217208905336

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The purpose of this paper is to obtain analytically minimum-weight plastic designs of simply supported continuous beams subjected to one single moveable load. The designs are established for ideal sandwich beams made of a rigid perfectly plastic material, on the basis of the sufficient condition for minimum-weight given by Save and Prager (6). The obtained minimum-weight designs are compared with plastic designs of beams with constant cross section.

ISSN:0360-1218    

DOI:10.1080/03601217208905337

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor