Gravity and Mass

The materials’ specific weight is automatically defined by the program for the calculation of the distributed self-mass of the structure. More, in the Beams, additional distributed load may also be defined, which will serve to define any load not associated to the self-weight of the structure (e.g. finishings, infills, variable loading, etc). Finally, the slab’s loads (self weight, additional gravity and live loads) are applied directly to the beams that support the slab.

Here, it is possible for users to define which degrees of freedom are to be considered in the analyses.

Gravity Settings
In SeismoBuild loads are defined explicitly in the Slabs  and Beams modules of the Building Modeller.

The user may define the value of acceleration of gravity ‘g’ (which is to be multiplied by the masses in order to obtain the permanent loads). Clearly, for the vast majority of standard applications, the default value (g=9.81 m/s2) need not to be modified. The direction of the gravity forces is considered in the -z direction.

Mass Settings
When running analyses, it may sometimes come handy to have the possibility of constraining the dynamic degrees-of-freedom to only a few directions of interest, in order to speed up the analyses or avoid the development of spurious response modes in those directions where the structural mesh was intentionally not adequately devised or refined. This can be done here, by unchecking those dofs that are not of interest (by default, all dofs are activated, i.e. checked).

Note: Stress-recovery ( Elements > Carry out Stress Recovery) may be employed to retrieve correct internal forces when distributed loads are defined (through the definition of material specific weight or of sectional/element additional load).