Shell and spatial structures: Between new developments and historical aspects

Advanced structural systems are more and more devoted to light, versatile, eco-sustainable structures. This goal can be achieved through the use of newmaterials and new approaches for structural optimization, form finding, design, andvalidation. Shell and spatial structures are representative of some of themost efficient structural systems in which the optimized use of materials is combined with effective structural forms and shapes. The ongoing development of analysis methods, design approaches and construction techniques of shell and spatial structures has resulted in an increasing interest from engineers, architects, and builders. This Special Issue is devoted to papers coming from a call principally addressed to the participants of the 1st Italian Workshop on Shell and Spatial Structures (https://sites.google.com/view/iwss2020/home) held online the last June 2020 after the lockdown restriction due to the Covid-19 pandemic (Figure 1). The experience of the first IWSS (IWSS2020) was particularly innovative. It brought together the interests of the Italian and the international community devoted to the study and applications of shell and spatial structures. The IWSS received two significant endorsements, from the IASS (www.iassstructures.org) and from the SISCO (www. siscoscienzadellecostruzioni.org). The pandemic emer-