A method of generation of starting arrangements in a problem of structure modelling of systems of densely packed objects

Authors

Keywords:

mathematical modelling, quasi -function, non-oriented convex polytopes, objects dense packing

Abstract

In this paper a mathematical model of a dense packing problem of non-oriented convex polytopes into a cuboid of minimum height is constructed by using the quasi Ф-function.

An application of quasi Ф-functions allows to formulate mutual non-intersections conditions for a pair of objects as a set of inequalities systems left sides of which are infinitely differentiable functions. Owing to this fact a mathematical model of the problem is presented as a classical non-linear programming problem.

For construction of different starting points a special method is proposed. The method includes three stages. On the first and second stages helper problems are solved. The first helper problem allows us to find a covering of polytopes by spheres of minimal radius. The second one allows us to find a dense packing of spheres in an  arrangement region. At the third stage parameters of separating planes between the dense packing spheres are calculated.

In order to find local extrema of the helper problems the IPOPT library is used.

References

Williams, S. R., Philipse, A. P. (2003). Random Packings of Spheres and Spherocylinders Simulated by Mechanical Contraction. Phys. Rev. E., 67, P. 051301. 2. Torquato, S. (2000). Modeling of Physical Properties of Composite Materials. Int. J. Solids Struct., 37, 411–422. 3. Yi, Y. B, Wang, C. W., Sastry, A.M. (2006.). Compression of Packed Particulate Systems: Simulations and Experiments in Graphitic Li-ion Anodes. Journal of Engineering Materials and Technology, 128, 73–80. 4. Li, S. X., Zhao, J. (2009). Sphere assembly model and relaxation algorithm for packing of non-spherical particles. Chin J Comput Phys., 26(3), 167–173. 5. Korte, A. C. J., Brouwers, H. J. H. (2013). Random packing of digitized particles. Powder Technology, 233, 319–324. 6. Jia, X., Gan, M., Williams, R. A., Rhodes, D. (2007). Validation of a digital packing algorithm in predicting powder packing densities. Powder Technology, 174, 10–13. 7. Bennell, J., Oliveira, J. (2008). The geometry of nesting problems: A tutorial. European Journal of Operational Research, 184, 397–415. 8. Stoyan, Yu. G., Chugay, А. М. (2012). Mathematical modeling of the interaction of non-oriented convex polytopes. Cybernetics and Systems Analysis, 48(6), 837–845. 9. Scheithauer, G., Stoyan, Y., Romanova, T. (2005). Mathematical modeling of interactions of primary 3D geometric objects. Cybernetics and System Analysis, 41(3), 332–342. 10. Wachter, A., Biegler, L. T. (2006). On the implementation of a primal-dual interior point filter line search algorithm for large-scale nonlinear programming. Mathematical Programming, 106(1), 25–57.

Published

2014-09-11

Issue

Section

Applied mathematics