Dakar Mosque gridshell: Exploring the benefits of the improved multibody rope approach through postbuckling analysis

This paper presents a comparative study of a gridshell roof structure designed for the Islamic Cultural Center in Dakar, Senegal. The structure, conceived by Fragomeli & Partners, emulates the shape of a dune to seamlessly integrate with the surrounding environment. To define an optimal structural shape while preserving the architectural intent, two form-finding methodologies were employed. The first method, the Multibody Rope Approach (MRA), enables the calculation of the funicular structural shape in response to the imposed load configuration. The second method, Improved MRA (i-MRA), introduces slight geometric variations to the funicular shape to reduce the diversity of structural elements required for construction. This work investigates the impact of the geometric distortions introduced by i-MRA on structural stability. Linear buckling modal analysis has been conducted on the two generated geometries, taking into account various loading conditions and structural element slenderness. Through incremental load Geometrical Non-linear with Imperfection Analyses (GNIAs) the equilibrium paths are examined to analyse the postbuckling behaviour of the gridshells. In the final step, the elastoplastic constitutive law is incorporated to assess also the impact of material non-linearity. The models are examined through incremental load Geometrical and Material Non-linear Analyses (GMNIAs). The results indicate that the i-MRA geometry exhibits a more even stress distribution and better qualitative postbuckling behaviour.