Mass elements - lmass & dmass

As indicated in the 'Materials' module, users have the possibility of defining the materials specific weights, with which the distributed self-mass of the structure can then be calculated. More, in the 'Sections' module, additional distributed mass may also be defined, which will serve to define any mass not associated to the self-weight of the structure (e.g. slab, finishings, infills, variable loading, etc). Here, lumped (lmass) and distributed (dmass) mass-only elements can also be defined and then added to the structure in the 'Element Connectivity' module, so that users may model mass distributions that cannot be obtained using the aforementioned Materials/Sections facilities; e.g. water tank with concentrated mass on top.

• Lumped mass - lmass
• Distributed mass - dmass
  

Note: Analyses of large models featuring distributed mass/loading are inevitably longer than those where lumped masses, and corresponding point loads, are employed to model, in a more simplified fashion, the mass/weight of the structure. If users are not interested in obtaining information on the local stress state of structural elements (e.g. beam moment distribution), but are rather focused only on estimating the overall response of the structure (e.g. roof displacement and base shear), then the employment of a faster lumped mass/force modelling approach may prove to be a better option, with respect to its distributed counterpart.