## 6 Conclusions  
This work presents the most relevant aspects of the structural behaviour of triaxial elastic long-gridshells made of timber (TEL-gridshells), an innovative gridshell concept that uses three directions of bent laths and rests exclusively on its short sides. The construction and load testing of a full-scale TEL-gridshell laboratory prototype have demonstrated the feasibility of the concept and served as a basis for the development of the numerical models. FEM models are presented for structural analysis and form-finding of TEL-gridshells, considering the actual eccentricity and slip at the joints by means of a series of aligned couplings with springs. The results of the first model, which replicates the actual geometry of the lab prototype obtained from experimental measurements, show that the most influential aspect on the overall deformability of the TEL-gridshells is the integration of the supporting structural elements, followed by the consideration of the semi-rigidity of the grid nodal joints. The incorporation of the semi-rigidity of the transverse members' joints has turned out to be the least relevant aspect. A reasonably good fit between numerical and experimental results has been achieved when the supporting structural elements of the TEL-gridshell and the semi-rigidity of all joints, considering a linear behaviour of the latter, have been included in the model. The second model developed proposes a methodology to reproduce the construction process of TEL-gridshells. It is based on an analysis by stages at large deformations using temporary supports and contraction cables with reduced stiffness to produce the deformation of the elements, and a system of additional couplings to connect the elements to each other after the curving process. The methodology has been successfully implemented  
Figure 18: Model B: residual normal forces in the three laths forming the transverse members. Upper lath (**left**), middle lath (**centre**) and lower lath (**right**). in the simulation of the prototype construction and has proven to be a viable procedure for form-finding and for determining the residual forces of this type of structure. Numerical analyses have provided further insight into the structural behaviour of TEL-gridshells. A parametric analysis would be necessary to draw general conclusions. However, the results obtained allow pointing out some of the main aspects to be considered in the design and structural analysis of this specific type of gridshells:  
* Transverse members are essential to maintain the target shape of the grid. They take on non-negligible normal stresses after the formwork is removed (relaxation);
* These structures have a natural lack of out-of-plane bending stiffness at the longitudinal edges. It is important to consider some solution to increase the stiffness in this area, such as additional layers in the transverse members;
* The stiffness of the structure is strongly influenced by the stiffness of the supporting elements. It is necessary to incorporate these elements in the numerical model to analyse the deformability of the structure. From a design point of view, it is advisable to look for solutions with the highest possible stiffness;
* Higher joint stiffness increases axial forces and decreases bending forces in the members, which is generally desirable;
* The worst stresses in the members correspond in general to the construction process. The most critical elements are the transverse members, which require the most attention in the design process of this type of structure. Despite being made up of thin baths, they have the highest curving stresses due to their small curvature radius. In addition, they also exhibit the highest bending stresses under external loads;
* The longitudinal grid members have significant bending moments in both strong and weak axes due to the construction process. However, due to the external loads, bending occurs mainly in the weak axis.