Advanced analysis and design of structures

Structural design is typically performed using a two step process. Firstly, a structural analysis is performed to determine the internal forces and moments and secondly, design checks are conducted on the individual elements that constitute the structure.

Two alternative approaches that utilise advanced structural analysis and streamline the design process into a single step and avoid the need for individual member checks have been developed within the Steel Structures Research Group. These are summarised below

Design by advanced analysis with strain limits

In this approach, cross-section classification is eliminated and design is based on beam element geometrically and materially nonlinear analysis with imperfections (GMNIA), utilising strain limits to mimic local buckling. In this fashion, the spread of plasticity both within cross-sections and throughout the structure (i.e. force and moment redistribution) is captured by the strain limit, which is determined based on the cross-section slenderness from the continuous strength method.

Design by advanced analysis with stiffness reduction

In this approach, the influence of imperfections, residual stresses and spread of plasticity is represented through stiffness reduction. A second order elastic analysis with stiffness reduction may hence be employed the design a structure directly, without the need for subsequent member checks. Further details can be found in the following papers.

Kucukler, M., Gardner, L. and Macorini, L., 2014. A stiffness reduction method for the in-plane design of structural steel elements. Engineering Structures, 73, 72-84.

Kucukler, M., Gardner, L. and Macorini, L., 2016. Development and assessment of a practical
stiffness reduction method for the in-plane design of steel frames. Journal of Constructional Steel
Research, 126, 187-200.

Kucukler, M., Gardner, L. and Macorini, L., 2015. Lateral–torsional buckling assessment of steel beams through a stiffness reduction method. Journal of Constructional Steel Research, 109, 87-100.

Kucukler, M., Gardner, L. and Macorini, L., 2015. Flexural–torsional buckling assessment of steel beam–columns through a stiffness reduction method. Engineering Structures, 101, 662-676.