DIFFERENCES IN ELASTIC BEHAVIOR BETWEEN PENTAGONAL AND DECAGONAL QUASI-CRYSTALS

Character tables and stereographic projections for five pentagonal and seven decagonal point groups have been given. According to our character formulas for quasicrystal tensors, the elastic constants up to cubic order have been deduced. By generalized elasticity theory, linear elastic energies, Hooke's laws, and equilibrium equations have also been obtained. The results show, like trigonal and hexagonal point groups, both five pentagonal and seven decagonal point groups can be divided into two Laue classes. They are 5, 5̄ and 5m, 52, 5̄m; 10, 10̄, 10/m and 10mm, 10 2 2, 10̄m2, 10/mmm, respectively, and all the point groups belonging to the same Laue class possess the same elastic properties. © 1995 The American Physical Society.