We design built-up wooden columns according to the simplified procedures of standard SIST EN 1995-1-1. In general, there are three types of pressure-laden elements. These are elements connected along the entire length, occasionally connected elements with spacers and lateral cross supports and truss pressure elements. The program created in Microsoft Excel enables the analysis of elements connected along the entire length, which are theoretically pin jointed at the ends. If we consider different buckling lengths, we can capture otherwise supported columns. You can choose between box section and I section. These are doubly symmetrical and centrally loaded so that the stress is assumed constant throughout the section. The components of the cross-section are connected to each other by single- or double-stranded binders, in which the characteristic resistance in one shear plane is determined as the minimum value of resistance determined for several possible failure modes of the binder or wood in its surroundings. Mechanical fasteners are selected based on dimensions of cross-section, type of wood and size of the load. The load-bearing capacity of the column depends mostly on the relative slenderness of the element and rigidity of the connection between wooden elements. Properties of the built-up column are captured by the effective bending stiffnes.
We enter into the program the geometry of the cross-section, the height of the built-up column, the design load, the type of wood, the duration of the load, the class of use and the type of fastener. The program controls normal stresses of the vertical elements by taking into account the bending of column and the proof of the load-bearing capacity of mechanical fasteners around both axes.