The optimization of shell structures remains a subject of extensive research. When considering variable loads, existing models and methods reach their limitations. Due to the complex interdependencies and interactions of multi load case scenarios, form-finding for compression-only shells often focuses solely on self-weight and constant loads. The dimensioning of the cross section usually takes place after the form-finding, to accommodate all relevant load cases. This paper presents a first investigation of an integrated shape- and thickness-optimization for multi load-case scenarios. The basic idea is an alternative formulation of the spring elements in the particle-based simulation. The direction of force remains collinear to the spring direction to ensure compression-only elements. However, the exerted spring force is no longer calculated from the element’s individual elongation. This adaptation allows the manipulation of the force flow within the structure while preventing horizontal displacement of the particles. Limiting the particle’s degrees of freedom facilitates to adjust the load cases‘ individual thrust-lines, to effectively reduce the enveloping cross section.
The paper describes the fundamental concept, mechanism, and the first digital exploration. The individual steps are illustrated using an exemplary 2D arch structure. The research holds potential of increasing the efficiency of structures significantly. It can eliminate the necessity for the constant loads to be the sole decisive load in shape-optimization, opening up a wide field of new application scenarios. Consequently, comparatively lightweight but compression-resistant materials may also become appealing for compression-only structures.