The influence of hopper eccentricity on silo discharge has always concerned researchers. Eccentric discharge brings about asymmetries in the distribution of normal pressures, the values of which are not known with precision. This study presents a three-dimensional model of the dynamic discharge of a silo with an eccentric hopper, considering the Drucker-Prager plasticity model for the behavior of stored material. The results obtained for different hopper eccentricities reveal that pressures decrease in the hopper along the generatrix of the silo above the outlet, as compared to the opposite side. An increase in normal pressures occurs at this generatrix, as compared to the diametrically opposite generatrix, in the lower part of the cylindrical wall above the silo-hopper transition.

Greenhouses had to be designed to sustain permanent maintenance and crop loads as well as the site-specific climatic conditions, with wind being the most damaging. However, both the structure and foundation are regularly empirically calculated, which could lead to structural inadequacies or cost ineffectiveness. Thus, in this paper, the structural assessment of a multi-tunnel greenhouse was carried out. Firstly, wind loads were assessed through computational fluid dynamics (CFD). Then, the buckling failure mode when either the European Standard (EN) or the CFD wind loads were contemplated was assessed by a finite element method (FEM). Conversely to the EN 13031-1, CFD wind loads generated a suction in the 0–55° region of the first tunnel and a 60% reduction of the external pressure coefficients in the third tunnel was not detected. Moreover, the first-order buckling eigenvalues were reduced (32–57%), which resulted in the need for a different calculation method (i.e., elastoplastic analysis), and global buckling modes similar to local buckling shape were detected. Finally, the foundation was studied by the FEM and a matrix method based on the Wrinkler model. The stresses and deformations arising from the proposed matrix method were conservative compared to those obtained by the FEM.

This paper addresses the lack of attention paid by the scientific community to the optimization of timber structures, specifically in the context of large-span agro-industrial constructions. The study focuses on the optimization of a three-dimensional roof composed of GL32h glulam regular double-tapered beams and purlins. Firstly, MATLAB was employed to develop a calculation software and then run the proposed optimization model based on genetic algorithms, in order to optimize the different geometries of the construction elements based on cost, as well as the optimum arrangement of the purlins and the number of beams. Moreover, statistical analyses were carried out on more than 200 optimization data points to uncover the influence of different variables in the optimization process. It was found that the snow load and span have a significant influence on the prediction of the height and width of beams and purlins, as well as the purlin spacing; while, as expected, the roof length also influences the optimal number of beams. All these findings could promote the use of timber structures; thus, achieving more sustainable and efficient construction practices.

The double-step joint is among the most frequently used layouts, within carpentry joints, for transmitting higher forces that would allow a single notch. They are especially effective in heavy timber structures. Nowadays, computer-aided manufacturing is being used more often, demanding further progress in its understanding. The conventional design of these joints is conducted by using simplifying assumptions, in particular regarding the shear stress distribution. This is overcome by the use of strength reduction coefficient, which is currently under study. Numerical simulation and experimental tests were carried out with heavy timber cross-sections for rafter to tie-beam truss joint. They were manufactured in glue-laminated timber owing to the large cross-sections tested. Experimental load-strain and load-displacement diagrams were compared with numerical results. This allowed observing the great shear stress concentration produced in the failure by shear crack, which suggests the application of conservative shear strength reduction coefficients.

This work provides the values of both the static and the kinetic friction coefficients for chestnut (Castanea sativa Mill.) of Spanish origin. Knowledge concerning these coefficients has its main application in the study of agroindustrial structures and machinery with timber members in contact. This determination was developed taking into account the timber anisotropy to establish surfaces and directions of slipping. A modified direct shear test device was used to conduct the tests and reproduce the tribological system. This procedure was functional and reliable and considered suitable for standardizing the friction measurement between timber surfaces, since this device is widely distributed in geotechnical and materials laboratories and the European codes do not specify a procedure or device to carry it out. The average values obtained were 0.46 for the static coefficient and 0.33 for the kinetic one, without considering the surfaces and directions of slipping. These values ranged between 0.36 and 0.55 for the static friction coefficient and between 0.28 and 0.39 for the kinetic friction coefficient depending on the direction considered and also taking into account the anisotropy of the timber. A good correlation was obtained between both coefficients, thus allowing for the estimation of the kinetic coefficient from the static one.