Damage Analysis and Evaluation of High Strength Concrete Frame Based on Deformation-Energy Damage Model

Huang-Bin Lin,Cheng Lan,Shou-Gao Tang

doi:10.1155/2015/781382

Abstract

A new method of characterizing the damage of high strength concrete structures is presented, which is based on the deformation energy double parameters damage model and incorporates both of the main forms of damage by earthquakes: first time damage beyond destruction and energy consumption. Firstly, test data of high strength reinforced concrete (RC) columns were evaluated. Then, the relationship between stiffness degradation, strength degradation, and ductility performance was obtained. And an expression for damage in terms of model parameters was determined, as well as the critical input data for the restoring force model to be used in analytical damage evaluation. Experimentally, the unloading stiffness was found to be related to the cycle number. Then, a correction for this changing was applied to better describe the unloading phenomenon and compensate for the shortcomings of structure elastic-plastic time history analysis. The above algorithm was embedded into an IDARC program. Finally, a case study of high strength RC multistory frames was presented. Under various seismic wave inputs, the structural damages were predicted. The damage model and correction algorithm of stiffness unloading were proved to be suitable and applicable in engineering design and damage evaluation of a high strength concrete structure.

Highlights

Structural concrete is a material with quite outstanding cumulative damage characteristics; damage development and damage accumulation under different conditions are fundamental for understanding structural failure
To better simulate the dynamic performance of a high strength concrete structure, the dependency of the unloading stiffness and ductility coefficient is analyzed after being introduced into the IDARC program
In this paper, based on the deformation-energy damage model and using experimental test data, we determined the expressions for the coefficient of the cyclic load effect and values required for the double parameter damage model of members of a high strength reinforced concrete column member

Summary

Introduction

Structural concrete is a material with quite outstanding cumulative damage characteristics; damage development and damage accumulation under different conditions are fundamental for understanding structural failure. Formula (6) was used to calculate modified parameters for the deformation-energy damage model The IDARC program for structural damage analysis had been used to simulate the earthquake response of a frame structure collocated with a high strength concrete column. To better simulate the dynamic performance of a high strength concrete structure, the dependency of the unloading stiffness and ductility coefficient is analyzed after being introduced into the IDARC program. From the deformation properties and the restoring force model tests of high strength concrete columns, Figure 5 shows the relationship between the structural member stiffness and number of unloading cycles; it indicates that the variation of Ku(x) shows changes consistent with linear drag. This paper used the modified double parameters damage index and calculated the indices using the embedded computing methods (a), (b), and (c) for comparison

Structural Nonlinear Dynamic Analysis Results

Conclusions

Conflict of Interests