关键词: 海洋平台结构钢, 解理断裂, 局部法, 威布尔应力, 有限元

Abstract: Theoretical basis of local approach developed by Beremin is first reviewed, then the methodology determing two parameters of Beremin model-Weibull exponent and critical cleavage stress σu are described. Based upon investigation on weld metal in the welded joints prepared with A537 steel welded electrode LB52NS the local approach is discussed. Later, the values of the Weibull stress at cleavage fracture are derived from tensile tests of axisymmetrically notched specimens R=1.25, 2.50 and 6.40mm) at low temperatures and finite element calculation. Finally good fit for the parameters m and σu between experimental and theoretical distribution are defined in accordance with statical analysis. The parameters obtained can be used in design against brittle failure and safety assessment of welded construction.

Key words: Cleavage fracture, Finite element, Local approach, Offshore structure steel, Weibull stress