3D-DEM을 이용한 코크 파쇄현상 시뮬레이션

Abstract

The compression and cleavage experiment and simulation of cylindrical coke sample are carried out to get the stress-strain curve for investigation of failure phenomena of coke. As it is well known that coke’s strength is mainly influenced by strength of coke matrix texture and porosity, compression and cleavage tests of cylindrical coke with various sizes of pore and pore location are simulated using 3-dimensional discrete element method (DEM) to examine the effect of pores to the strength of coke and to investigate the failure pattern, and simulated results are discussed by comparing with experimental results.The following assumptions are applied to express a breakable coke sample using unbreakable sphere shape particles. Coke matrix is an aggregation of thousands of small sphere particles, and the void between the particles is considered as pore. The particles are connected to each other by elastic bonds at every contact sites to be broken when normal or shear stress exceeds its corresponding bond strength. To make strongly bonded but highly porous material, large pores are inserted intentionally, and the effect of pore on the coke strength has been investigated by regulating thier size and location of the large pores. According to simulation results, porosity is the most dominant factor for coke strength as compared with the strength of coke matrix texture

When pores are distributed regularly it shows somewhat higher coke strength than randomly arranged pores’ case. In the cleavage test, critical strength of coke sample is proportional to the exponential of porosity and minimum coke matrix area fraction of cross section.