Research On Resistance Of Progressive Collapse Of Damaged Grillage

Accidental damage is unavoidable to grillage structure during running. Preventing damaged grillage from progressive collapse has raised common concern in the industry. IMO requires to testify the grillage structure designed according to the upcoming HCSR have the capacity of resisting progressive collapse.The paper firstly reviews the research status at home and abroad of progressive collapse, analyzes and compares the damage of grillage structure. Two damage modes is proposed. According to the buckling evaluative method in HCSR, the assessment criteria and computational methods for preventing damaged grillage from progressive collapse are proposed. We compiled a buckling utilization factor calculating program, which has been used for the calculating the grillage of several CSR hulls. The results show that the grillage designed according to the codes still has sufficient resistance to progressive collapse after partial damage. Combined with the calculation results of the CSR hulls and based on appropriate assumptions, and simplifications, the section modulus formula,in which the damage of a stiffener will not cause the buckling of the adjacent stiffener, is deduced by overload law.