Proceedings in applied mathematics and mechanics, 19 (1), 1-2 Proceedings in applied mathematics and mechanics : PAMM 19(1), e201900167 (2019). doi:10.1002/pamm.201900167 special issue: "Special Issue: 90th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) / Issue Edited by: J. Eberhardsteiner, M. Schöberl"