## 5 Conclusions  
In this paper, the applicability of the seismic provisions of the current codes for the nonstructural components of single-layer spherical reticulated shells was analysed. The acceleration response spectra of the nodes in the shell were studied, a seismic design method was proposed for the nonstructural components in a shell with a roofing system, and the following conclusions were obtained:  
1. The applicability of Chinese, American, and European codes to the seismic design of the nonstructural components in single-layer spherical reticulated shells was analysed. The current codes are mostly based on the characteristics of horizontal floor response spectra of multistorey or high-rise buildings. The acceleration response characteristics of a node in a reticulated shell structure are significantly different from those suggested in the codes, so the current codes cannot be directly applied. 2. The roofing systems influence the dynamic performance of the shell and affect the seismic acceleration response of the shell node in each ring. The constraints of the bolted purlin roofing system are relatively weak, and the horizontal and vertical acceleration response characteristics of the shell with a bolted purlin roofing system are close to those of the shell without a roofing system. The seismic response of the shell nodes is obviously affected by the high-order vibration modes of the shell, which are not fully considered in the current codes. The phenomenon of the shell nodes near the support where the horizontal acceleration response exceeds the specification requirements is more serious. The reticulated shell structures are more sensitive to vertical seismic excitation, which leads to an increase in the vertical acceleration response as the ring approaches the central node of the shell. The strength and stiffness of the purlin joint in a welded purlin roofing system are larger, the dynamic characteristics of the shell will more obviously change, and the membrane stiffness and out-of-surface bending stiffness of the shell nodes will significantly improve. The seismic action can be transmitted more efficiently in the shell with a welded purlin roofing system, leading to the phenomenon that the horizontal and vertical acceleration response of the shell nodes tend to increase as the ring approaches the central node of the shell. 3. The acceleration response spectra of the shell node under three-dimensional ground motions were theoretically analysed based on the complete quadratic combination method. The difference in the membrane stiffness of the shell node in different directions will affect the seismic response of the shell node near the support, and the  
Figure 15: Comparison of acceleration response spectra of spherical reticulated shells: (**a**) D6053-LSWM horizontal; (**b**) D6053-LSWM vertical; (**c**) D6053-HHWM horizontal; (**d**) D6053-HHWM vertical; (**e**) D8031-LSWM horizontal; (**f**) D8031-LSWM vertical; (**g**) D8031-HHWM horizontal; (**h**) D8031-HHWM vertical. influence of the membrane stiffness of the shell nodes and the seismic input direction should be considered in the analysis of the acceleration response spectra of the shell nodes near the support. In this paper, the calculation method for the acceleration response spectra of the nodes in a single-layer spherical reticulated shell without a roofing system was proposed. * In the shell with a bolted and welded purlin roofing system, the larger the rise-to-span ratio of the shell with the same span, the higher the shell node height and shorter the horizontal distance in the same ring from the support. This leads to the phenomenon that the horizontal amplification coefficients (\(AF_{0}\)) of the seismic acceleration amplitude for the representative node in each ring of the shell tend to increase with the increase in the rise-to-span ratio and that the vertical amplification coefficients of a shell with a \(1/3\) rise-to-span ratio are smaller than those of the shells with other rise-to-span ratios.