Numerical investigation of solid bulk cargo liquefaction

Abstract

Liquefaction of fine particle cargoes such as unprocessed nickel ore and iron ore, resulting in cargo shift and loss of stability of ships, has caused the loss of many lives in marine casualties over the recent few years. In the paper, the DEM liquefaction model is presented, followed by experimental data to validate the model by given three assumptions: each sphere is regarded as a hypothetical assembler of particles; the radius of the particle can be scaled with the elastic-plastic strain according to the stress on the particles in PFC based on the UBCSAND model; various friction coefficients are used to represent various moisture contents. The whole liquefaction process can be addressed by this model to capture the characteristics of the cargo from initial state to liquefied state, and the interaction between cargo shift and the response of the 2D rectangular structure. A parametric investigation is undertaken to identify the key parameters (frequency, amplitude and moisture content) that trigger cargo liquefaction.