Design Of Cable Structures Research Articles

Application of Chebyshev Series to Solution of Cable Vibration Problems

In order to obtain simple formulae of cable dynamic behavior for numerical computation, the Chebyshev series method for the free vibration analysis of a cable considering boundary condition and flexural stiffness is utilized. The differential eigenvalue problem is reduced to an algebraic system which gives approximate eigenfrequencies and mode shape functions for a cable. These simple and approximate formulae are of value in the analysis of cable dynamic response and may be proved useful in the design of cable structures. The proposed approach is applicable to a wide range of cables.

Optimal Design of Cable Structures with Genetic Algorithms

Genetic Algorithm is employed for cable structures subjected to large displacements, stress and diameter constraints. Design solution is governed by nonlinear interaction of cable sag, amount of pretension and stiffness of cable with deformations under transverse loads. Geometrical nonlinear finite element method with total Lagrangian approach is integrated in the present work with genetic algorithm to evaluate optimum values of design parameters, i.e. diameter of cable and amount of prestress. Study is performed on steel and carbon fibre cable stays, cable nets and cable roofs. Different types of crossover operators are applied along with single- and multi-level optimization techniques in order to obtain true optimum in the search space of global optimum.

Stochastic strength and fatigue of fiber bundles

Stochastic models for the failure of single fibers and fiber bundles are considered with a historical perspective. All surviving fibers in the bundle at any time t are assumed to share the load equally. Of particular interest is the tensile strength and time to failure in fatigue of such fibers and bundles. The stochastic model for the failure of single fibers is shown to have realistic features and a very favorable evaluation of the model is carried out using recently reported experimental data. Using asymptotic results for bundles which were recently obtained by the author, bundle failure is compared with single fiber failure. Many behavioral features carry over from fiber to bundle. But bundle lifetime is typically far less under fatigue loadings, though a moderate reduction in bundle load restores the lost lifetime. Most important, the variability in bundle lifetime and strength is inversely proportional to the square root of the number of fibers in the bundle. The results have implications in the design of cable structures.

Analysis and design of cable structure S

As a class, suspension structures are generally more flexible than framed or trussed structures. A consequency of this flexibility is that factors often need be considered when engineering cable structures which may be neglected when designing more conventional structural systems. Among these factors are: difficulties associated with mathematically defining the suspension structure's initial shape and the member forces corresponding to that state, the nonlinear relationship between changes of loading and displacement, and the susceptibility of some types of cable structures to wind-induced oscillations. In the paper, cable structures are classified and examples of some types are illustrated together with a discussion of their advantages and disadvantages. The problem of establishing the initial shape of the structure is discussed. Some techniques for computing the displacements of suspension structures resulting from changes in static loading, considering the geometrical nonlinearity, are described. A procedure for determining the displacements of stiffened and unstiffened cable three-dimensional structures is outlined that is suitable for computer solution. Results of numerical studies made utilizing this technique are presented.