A MODEL OF DAMAGE AND CREEP INTERACTION IN A QUASI-BRITTLE COMPOSITE MATERIAL UNDER AXIAL LOADING

摘要

Creep is the time-dependent, viscoelastic strain observed in materials under constant stress. Creep can increase structural strains/deformations to non-serviceable levels or alter the stress distribution among structural components. While stress redistribution can be helpful in composite materials by relieving the stress on one component, it might have a detrimental effect on another, especially if it leads to overstress-ing. A step-by-step in time approach for modeling creep in quasi-brittle materials such as concrete and masonry is utilized, and a new continuum damage model based on Weibull's failure rate distribution is introduced. A multiplicative approach to integrate the creep and damage effects within the step-by-step in time analysis is invoked. The significance of the proposed approach is exemplified through analysis of a clay masonry column filled with grout and subjected to concentric axial load. It is shown that the proposed approach can provide insights on the stress evolution in both components of the composite material that might not be inferred using classical methods of analysis.