An approximate finite element method is developed for analyzing the distortional buckling of doubly symmetric I-section beam-columns. The method allows an analysis to be made of elastic uniform members under various conditions of loading, end support, and restraint. A computer program based on this finite element method is described, and the convergence and accuracy of the buckling solutions are demonstrated. The method is then used to investigate the significance of different end conditions on the elastic buckling of I-beams under uniform moment.

The reliability of buildings under winds is evaluated. The uncertainties in terms of the first and second statistical moments are included in the formulation. The dynamic response of the structure is obtained based on a random vibration analysis. In estimating the statistics of the wind load effects, uncertainties in the wind environment parameters and dynamic structural properties are considered. Risks of exceeding various safety and serviceability limit states are evaluated at critical sections of a 25 story steel building. Results indicate that uncertainties in the dynamic structural properties and wind environment parameters contribute significantly to the risk. The risk is also sensitive to the form of the extreme value distribution and errors in sampling and estimation of distribution parameters. The proposed method provides a tool for a comprehensive assessment of reliability of structures under wind loadings.

A computer program for the static and dynamic analysis of plane frames subjected to large inelastic deformations is reviewed. Nonlinear material, soil structure, and geometric effects are simultaneously considered. Problems are solved showing the influence of the stress-strain model on the static and dynamic response of frames subjected to large static load reversals and earthquake motions. Results indicate that while more accurate models are available for structural steel, the relatively simple Masing model is able to simulate the inelastic force-deformation response of frames quite well over a large range of inelastic deformations; even plastic-hinge models may predict accurate frame response.

Window glass design practice in the 1950s and 1960s was influenced to a large degree by manufacturers glass design charts, adopted by building codes and standards and utilized heavily by the design professions. In the 1970s, a changing design environment caused professionals to examine more closely design processes for window glass. Questions concerning wind loads, glass strength, failure risks, and window system behavior have prompted window glass designers to look beyond the glass charts for guidance. Problems exists because of the limited amount of data and information available on window glass in the open engineering literature. Activity in the field of wind engineering assists the designer with problems related to load definition, but troublesome problems remains, i.e., questions of glass strength, glass behavior under load, and acceptable failure risks.

The effects of out-of-roundness errors, that cab be introduced durning the construction of cooling tower shells, on the linear stress distributions are examined. Using a simplified, statically equivalent, simulation of nonaxisymmetric geometric imperfections, it is shown that circumferential bending provides the major contribution to the shell's resistance to the effects arising from these imperfections. It is shown how meridional membrane stresses are also severely affected; this is particularly so if a loss of circumferential moment capacity occurs. The mechanics of behavior in the presence of circumferential imperfections is clarified by a systematic study of the effects of a number of the separate parameters defining the imperfection geometry. As a consequence, suggestions are made as to how the various forms of behavior could be incorporated into future design practice, for the provision of rational tolerance limits for out-of-roundness errors.

Optimal designs of arches under multiple load cases using an automated design routine are presented. The design variables consist of geometric (arch shape) as well as member sizing variables (cross-sectional dimensions). The members are sized on the basis of working stress design procedure, and all the relevant provisions of the AISC specifications are met. The optimal arch shapes produced by the present method for a uniformly distributed load case show a good agreement with the theoretical results. The optimal designs under two and three load cases are also obtained. Under two load cases, the optimal shapes are not very different than a parabolic curve passing through the supports and crown of the arch.

An efficient method for the static and dynamic analysis of marine cable structures is presented. These structures may consist of floating platforms, buoys, weights, anchors, ect., interconnected by arbitrary arrangements of cables and flexible pipes. Displacements or forces can be specified at any number of nodal points and wave or current interaction can be simulated. The efficiency of the method has been demonstrated by serveral applications: dynamic response of a deepwater oil production platform, anchor drop, sonar towing, dynamic stiffness of mooring lines, tankers loading systems with flexible pipes, etc. Because the analysis technique is based on simple long curved cable elements, it outperforms all the currently available methods which use series of short straight links to model the cables.

Experimental test results are presented of the use of force limiting devices (FLD) on the compressive chords of two-layer space trusses. Two subassemblages and one full-scale truss were tested, and two types of FLD were used. The results are considered in terms of the truss load versus central deflection plots. These highlight the significance of lack of fit of members in causing initial member forces that furnish a reduction in truss load capacity at first yield, after which there may be no significant increased ultimate strength reserve. Conversely, when FLD's were used on the brittle-type compressive chords, improved overall ductility was obtained, and the deleterious effects of lack of fit were moderated owing to favorable force redistribution under ductile yield conditions.