In this lecture, we'll cover the following:

• How to define and compute the self-weight of a plate as a uniformly distributed load
• How to construct the distributed force vector for plate elements
• How to reuse a previously developed function to obtain equivalent nodal forces
• How to assemble the global force vector by looping over elements
• How contributions from multiple elements accumulate at shared nodes

In this lecture, we focus on building the global force vector representing the self-weight of a plate. We begin by defining the self-weight as a uniformly distributed load based on material density and plate thickness, and then express this as a distributed force vector acting on each element. Using a previously developed function, we compute the equivalent nodal forces for each element, which allows us to translate continuous loading into discrete nodal contributions.

We then assemble the global force vector by iterating through all elements, determining the appropriate degree-of-freedom indices for each node, and inserting the element-level force contributions into the correct positions. We observe how forces accumulate at shared nodes, with edge, corner, and interior nodes receiving different total contributions depending on how many elements meet at each location.

Next up

With the force vector assembled, the next lecture focuses on building the global structure stiffness matrix by assembling element contributions.