Growth of Smaller Grain Attached on Larger One: Algorithm to Overcome Unphysical Overlap between Grain

As a smaller grain, which is attached on larger one, is growing, it pushes also the larger one and other grains in its surrounding. In a simulation of similar system, repulsive force such as contact force based on linear spring-dashpot model can not accommodate this situation when cell growing rate is faster than simulation time step, since it produces sudden large overlap between grains that makes unphysical result. An algorithm that preserves system linear momentum by introducing additional velocity induced by cell growth is presented in this work. It should be performed in an implicit step. The algorithm has successfully eliminated unphysical overlap.Comment: 6 pages, 4 figures, conference paper (ICMNS 2014, 2-3 November 2014, Bandung, Indonesia

Binary Composite Fiber Elasticity using Spring-Mass and Non-Interacting Parallel Sub-Fiber Model

Composite materials have been investigated elsewhere. Most of the studies are based on experimental results. This paper reports a numerical study of elasticity modulus of binary fiber composite materials. In this study, we use binary fiber composite materials model which consists of materials of types A and B. The composite is simplified into compound of non-interacting parallel sub-fibers. Each sub-fiber is modeled as Ns point of masses in series configuration. Two adjacent point of mass is connected with spring constant k (related and proportional to Young modulus E), where it could be kAA, kAB, or kBB depend on material type of the two point of masses. Three possible combinations of spring constant are investigated: (a) [kAB < min(kAA, kBB)], (b) [min(kAA, kBB) < kAB < max(kAA, kBB)], and (c) [max(kAA, kBB) < kAB]. The combinations are labeled as composite type I, II, and III, respectively. It is observed that only type II fits most the region limited by Voight and Reuss formulas

Self-Motion Mechanism Of Chained Spherical Grains Cells

Cells are modeled with spherical grains connected each other. Each cell can shrink and swell by transporting its fluid content to other connected neighbor while still maintaining its density at constant value. As a spherical part of a cell swells it gains more pressure from its surrounding, while shrink state gains less pressure. Pressure difference between these two or more parts of cell will create motion force for the cell. For simplicity, cell is considered to have same density as its environment fluid and connections between parts of cell are virtually accommodated by a spring force. This model is also limited to 2-d case. Influence of parameters to cell motion will be presented. One grain cell shows no motion, while two and more grains cell can perform a motion.Comment: 4 pages, 6 figures, 1 table, conference paper (Submitted to The International Symposium on BioMathematics (Symomath) 2013, October 27-29, 2013, Bandung, Indonesia