This chapter develops the components required for successful modelling of temporary structures. It presents the principles, methods and the associated limitations that currently are seen as the state-of-the-art in structural analysis using the Finite Element Method. Material models of steel, aluminium and bamboo are presented with an emphasis on linear and multilinear models for steel and the Ramberg-Osgood model for aluminium. Models are presented for braces, props, beam-to-column connections, top connections, base connections and column-to-column connections based on the latest theoretical and experimental procedures developed by the authors and co-workers. Examples of two and three dimensional models are then developed for access scaffolds, bridge falsework and bamboo scaffolds. Finally, the chapter presents information on the effects of ground modelling and on advanced wind engineering using complex numerical methods.
Top4.1 Introduction
Structural analysis concerns the assessment of the internal forces and deformations of the structural system for a predefined hazard scenario, establishing the basis for the subsequent design verification compliant with the operational requirements set out in design codes for various design situations.
Structural analysis requires initially the definition of the typology of the structural system, which will then be simulated by an approximate conceptual model based on the theory of structural mechanics which impose the compatibility between material deformations and applied displacements and the equilibrium between internal forces and external actions. The basic input variables of the idealised model are the topology and geometry of the structural system and of its elements, the properties and spatial distribution of the materials used, the boundary conditions with the surrounding systems and the hazard scenario characteristics. The characteristics of the basic variables may change with time. Furthermore, uncertainties are always present due to our incomplete and insufficient knowledge of the real world.
Structural analysis involves the simulation of complex real structural system by approximate conceptual models trying to balance rigour and work feasibility.
This Chapter develops the numerical models used in design programs with a particular emphasis on the material models used for the temporary structures made of steel, aluminium and bamboo. Sub-models for various types of connections are developed and then applied in two and three dimensional models of access scaffolds and bridge falsework structures. The modelling of soil is addressed and finally the determination of wind pressures on scaffolding is introduced before conclusions in the Chapter.
On the basis of this Chapter it is expected that the reader will acquire knowledge on the following topics:
- 1.
Fundamentals of the Finite Element Method.
- 2.
Differences between types of analysis methods.
- 3.
Models of materials and of different connections of temporary works.
- 4.
Fundamentals of models of soil.
- 5.
Fundamentals of Computational Fluid Dynamics applied to temporary works.