Showing papers on "Portal frame published in 1975"

An Analytical Model for Determining Energy Dissipation in Dynamically Loaded Structures

Abstract: : An analytical procedure is developed which predicts nonlinear cyclic structural response under large reversals of plastic strains. The structure is discretized by means of the finite element approximation, and the material behavior is simulated by a refined analytical model which describes the realistic hysteretic stress-strain curves of A36 steel under arbitrary cycles of load. In order to test the validity of this material model some comparisons are made with experimental values of the inelastic response of a simply supported beam under cyclic bending. The model is subsequently used in the dynamic analysis of a portal frame subjected to a selection portion of the El Centro NS earthquake acceleration record.

Multi-storey car park design

Abstract: The authors discuss the factors influencing the design and choice of materials used in the construction of multi-storey car parks. Recommendations are given for the positioning of signs and columns to cause minimum obstruction and inconvenience. Minimum stall widths for unobstructed parking are suggested; clear markings are essential for full use of the static capacity. Floors should be watertight to prevent seepage; perimeter barriers should be capable of providing an effective resistance to a moving car which could be accelerating in bottom gear. Reasons for discarding designs using an uncased steel-formed structure with compositely designed pre-cast concrete floors are given. Cast in-situ concrete has been chosen for the frame and floors based on a two-pinned portal frame structure, constructed in a nominal module of 4.8 M. Floors have reinforcements to control shrinkage and cracking besides the main reinforcement in their ribs. Two types of frame are illustrated, system 1 with external columns and system 2 with inset tapered columns; the relative merits of each type are discussed. /TRRL/