Title: Biaxial Principal Stress Interaction Diagram for Reinforced Concrete Membrane Elements
Author(s): Ahmad Rahimian
Publication: Structural Journal
Appears on pages(s): 119-133
Keywords: biaxial stress; interaction diagram; limit state; membrane elements; principal stress; reinforced concrete; shear stress; shell elements
Advancements in finite element methods and research related to reinforced concrete (RC) elements have greatly facilitated the analysis and design of today’s increasingly complex concrete structures. However, the design criteria for shell elements under membrane actions are not explicitly identified in ACI 318-14. This paper presents an approach based on an interaction diagram of principal stresses to supplement the design of RC shell elements under membrane stresses. It provides a closed-form solution for creating the ultimate limit state boundary for an RC membrane element under biaxial and shear stresses. These boundary limits can then be used to evaluate the adequacy of the RC element for the applied loads. The proposed method is based on the well-known shear theories of the rotating angle softened truss model while considering aspects of the Modified Compression Field Theory and the concrete limit state under biaxial compression.