# Performance and Measurement Devices for Membrane Buildings in Civil Engineering: A Review
## 3 Performance
### Membrane Roof  
The transfer path of wind-induced loads on membrane roofs (i.e., conventional roofing assembly) falls into two categories: structural and pneumatic [8]. A mechanically attached roof system (MARS) is considered to have a structural load path. In this kind of system, the membranes are connected with the components through fasteners in the welding position, making this part most vulnerable to wind suction. It signifies that the welding method has a profound influence. The fastener-centered two-side welding system outperforms the unilateral system in terms of wind uplift rating since one-sided welding is prone to peeling, which should be avoided [60; 61]. The membrane-width-to-fastener-row ratio crucially influences the failure load of fasteners and is not affected by the size [33]. A partially attached roof system (PARS), in which the membrane clings to a mechanically attached component, is associated with a pneumatic load path. Different fixing methods for membrane materials do not result in the ballooning deformation of a PARS under wind loads such as in a MARS [8]. Curing time is the crucial parameter to determine PARS resistance to wind uplift. With an increase in curing time, the wind resistance of PARS shows an upward trend and eventually stabilizes [59]. Therefore, protective measures should be taken before reaching complete curing. [PERSON] et al. [8; 24] compared the differences between MARS and PARS through the Natural Hazards Engineering Research Infrastructure (NHERI) Wall of Wind (WOW) Experimental Facility (Figure 10) and in situ experiments. The pressures recorded on PARS were higher than those recorded on MARS but lower than those recorded on plywood roofs, indicating that the deformation of the membrane under load facilitates the relief of external pressures. The extent of reduction is determined by the position of the seam in a MARS [8]. Figure 9: Experimental methods of structural wind load response research [14; 58; 59]. Wind tunnels are utilized for most experimental programs on tensioned membrane structures. The models are classified as rigid or aeroelastic, depending on the material. Wind pressure is calculated by employing the rigid model, and wind-induced vibration is explored using the aeroelastic model [62]. Since the membrane structure easily deforms under external load, if the shape of the rigid model is an undeformed construction shape, the data obtained deviate from the actual situation. [PERSON] et al. [30] found that the positive pressure coefficient on the windward side was larger than that on the undeformed side by comparing the surface wind pressure data gathered from two rigid models of undeformed and deformed horn-shaped tension membranes, whereas the negative pressure coefficient on the leeward side was lower, which can be observed in Figure 11.  
During wind-induced vibration, the pattern of the surrounding airflow is altered by the membrane, causing the structure to oscillate at a lower frequency than in a vacuum,  
Figure 11: Coefficients of pressure on the surface [30]. Figure 10: NHERI Wall of Wind Experimental Facility [24]. an effect known as added mass [63; 64]. The added mass increases with the increase in wind speed and immensely impacts the displacement of the structure [62]. [PERSON] and [PERSON] [65] found that the additional mass could be up to 10 times the structural mass. However, contradictory results were reported by [PERSON] et al. [63]. The magnitude of the added mass in dynamic interactions was found to be almost the same as the mass of the structure, with the added mass in static interactions being smaller relative to the dynamics. Numerous vibration modes are typically excited by the wind, and the amplitude and damping ratio are positively proportional to wind speed [66]. Flutter occurs when the membrane deflects in a divergent direction and takes the shape of standing waves [67].