Dynamic Hysteretic Characteristics of High-Strength Steels (POSTEN60, POSTEN80) and Application of a Dynamic Hysteresis Model to FE Analysis

초록

As steel structures become larger, taller, and longer, the demand for high-strength steel increases. High-strength steels exhibit different mechanical characteristics and hysteretic behavior for dynamic deformation than for quasi-static deformation. This is attributable to the strain rate and temperature dependence of steel materials when nonuniformly deformed in the plastic region. Therefore, to analyze and design structures using high-strength steels under dynamic cyclic loading, such as earthquake loading, it is necessary to consider the special dynamic hysteresis model of high-strength steels. In particular, when using finite-element (FE) analysis programs one should use the proper material characteristics for those steels. In this paper, dynamic hysteresis models for standard high-strength steels, with tensile strengths of 600 and 800 MPa, are formulated based on results of tensile tests and low-cycle fatigue tests over a range of strain rates from 10-4-10 s-1. A three-dimensional elastic-plastic finite-element analysis program using a newly formulated dynamic hysteresis model is developed by the writers. Accuracy and validity of the developed finite-element analysis program is verified by correlation of the analytical and experimental results.

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