Analysis of Mold Overall Deformation and Contact Stress During Biomass Cold Compression Molding

Ansys is adopted to analyze mold deformation and stress field distribution rule during the process of compressing biomass under pressure of 20Mpa. By means of unit selection, material property setting, mesh partition, contact pair establishment, load and constraint applying, and solver setting, the stress and strain of overall mold are analyzed; meanwhile, the size as well as distribution of various contact stresses is explored. The mold deformation is small while the displacement of compression bar and compressed fuel is larger. Since displacement is the manifestation of overall deformation situation, the lower part of fuel will definitely be lower than that of upper part with the compaction of fuel, but the displacement of compression bar is the largest. Overall equivalent pressure diagram indicates that, the pressure on compression bar is the largest, followed by compressor; The pressure at the contact place of compressor and base is larger while other places is smaller so that it decreases in the form of semi circle. The contact stresses are various in different places of contact pair and the difference in some is large. However, fuel compression is a repetitive periodic process, so each contact pair will generate alternating stress, under which fatigue phenomenon may quickly occur in mold.