Original Contribution to the Structural Design of Tensile Membrane Structures for Large-Span Stadium Canopies in Tropical Climates: A West African Perspective

Tensile membrane structures offer architecturally expressive and structurally efficient solutions for large-span stadium canopy coverage, yet their design in West Africa's tropical climate is complicated by intense ultraviolet radiation, high thermal cycling amplitude, episodic high-intensity rainfall, and wind loading regimes that differ from the European and North American contexts that dominate the existing design guidance literature. This study makes an original contribution to the structural design of tensile membrane canopies for large-span stadia in tropical climates, developing a design methodology that integrates climate-specific material performance data, probabilistic wind load models derived from local meteorological records, and form-finding optimisation for structurally efficient anticlastic surfaces under combined gravity and lateral loading. Material characterisation tests on PTFE-coated glass fibre, ETFE foil, and PVC-coated polyester membranes were conducted under accelerated weathering conditions simulating 20 years of tropical exposure in Lagos, Port Harcourt, and Abuja. Probabilistic wind load models were developed using extreme value analysis of 40-year meteorological records from the Nigerian Meteorological Agency, incorporating convective storm loading that governs membrane canopy design in tropical environments differently from synoptic storm loading. Form-finding was conducted using the dynamic relaxation method, and nonlinear structural analyses under combined load cases were performed in Sofistik. The design methodology was applied and evaluated through a full-scale design case study of a 45,000-seat stadium canopy configuration. Results demonstrate that neglecting convective storm loading, which produces localised wind pressure peaks 37 percent above synoptic storm predictions, leads to under-designed membrane boundaries and mast connections. Keywords: tensile membrane structures, stadium canopies, tropical climate, form-finding, wind loading.