Plasticity and Fracture Behaviors of Marine Structural Steel, Part IV: Experimental Study on Mechanical Properties at Elevated Temperatures

doi:2011.25.3.66

J. Ocean Eng. Technol. > Volume 25(3); 2011 > Article

J. Ocean Eng. Technol. 2011;25(3):66-72.
DOI: https://doi.org/10.5574/KSOE.2011.25.3.066

Choung Joon-Mo,Im Sung-Woo,Park Ro-Sik

Dep't of Naval Architecture and Ocean Engineering INHA University,Steel Structure Research Lab. RIST,School of Naval Architecture & Ocean Engineering Ulasn University

조선 해양 구조물용 강재의 소성 및 파단 특성 IV: 고온 기계적 물성치에 관한 실험적 연구

정준모,임성우,박노식

인하대학교 조선해양공학과,포항산업과학연구원 강구조연구소,울산대학교 조선해양공학부

Keywords: initial yield strength, tensile strength, elastic modulus, reduction factor, elevated temperature, high transition temperature, blast wall

핵심용어: 초기 항복 강도, 인장 강도, 탄성 계수, 감소 계수, 고온, 고온 천이 온도, 방폭/방화벽

Abstract

This is the fourth of a series of companion papers dealing with the mechanical property reductions of various marine structural steels. Even though a reduction of the elastic modulus according to temperature increases has not been obtained from experiments, high temperature experiments from room temperature to $900^{circ}C$ revealed that initial the yield strength and tensile strength are both seriously degraded. The mechanical properties obtained from high temperature experiments are compared with those from EC3 (Eurocode 3). It is found that the high temperature test results generally comply with the prediction values by EC3. Based on the prediction of EC3, time domain nonlinear finite element analyses were carried out for a blast wall installed on a real FPSO. After applying the reduced mechanical properties, corresponding to $600^{circ}C$ to the FE model of the blast wall, more than three times the deflections were observed and it was observed that most structural parts experience plastic deformations exceeding the reduced yield strength at the high temperature. It is noted that a protection facility such as PFP (passive fire protection) should be required for structures likely to be directly exposed to fire and explosion accident.