DERIVATION OF RESISTANCE DEFLECTION RELATIONSHIP OF RC MEMBERS USING SOFTENING MODEL
The resistance-deflection function of RC members plays an important role in the structural dynamic response analysis against blast loads. Previous studies recommend the use of a quasi-static resistance function modified by dynamic increase factors (DIF). However, the DIF value is estimated by using averaged strain rates and a constant plastic hinge length of 0.7 times the depth of the cross section is assumed in the analysis although the loading rate profile is not a constant over a cross-section and hinge length is varying with loading conditions. In this paper, a new strain rate formula over cross-section of a member under blast loading is derived based on structural dynamics theory. A layered analysis model together with the derived strain rate effects over a cross-section is used to calculate blast resistance capacity of the RC member. A softening model with variable hinge length rather than constant hinge length is used to determine the curvature profile along the member.It is then integrated along the length to obtain the rotation at all points of the member. The rotation curve is then integrated along half the length of the member to determine the deflection at the centre of the member. For each of the points on the moment-curvature relationship the resistance is determined from the moment profile and the deflection by double integrating the curvature profile, resulting in a full resistance-deflection relationship for the member.
Soft model Resistance deflection curve Dynamic response Airblast load
Cheng-Qing Wu Deric John Oehlers
School of Civil, Environmental and Mining Engineering, The University of Adelaide,AustraliaManuscript Template for Isseye-10, Title in 10.5pt, Bold
国际会议
第十届国际结构工程青年学者研讨会(The Tenth International Symposium on Structural Engineering for Young Experts)
长沙
英文
500-505
2008-10-19（万方平台首次上网日期，不代表论文的发表时间）