Limit state analysis of reinforced concrete slabs by dual adaptive yield design approaches

This paper deals with adaptive mesh refinement for limit state analysis of reinforced concrete slabs. Two simple and efficient mesh refinement indicators are developed. Plastic dissipation power in terms of curvature rates is used as refinement indicator in the kinematic yield design. For pseudo-static yield design approach, a Nielsen yield function value-based refinement indicator is proposed. Various slabs with arbitrary geometries and boundary conditions are examined, showing that upper and pseudo-lower bounds on the actual collapse load factors are accurately computed with the optimal layout of elements, and hence minimizing computational effort. Collapse mechanisms in terms of plastic dissipation distribution (or element concentration) and moment fields at limit state, that are crucial information for slab design, are also presented.