Simply-supported beam P-δ
P-δ is a local effect associated with axial load on displacement relative to the element chord which extends between end nodes. Figure 1 illustrates the influence of P-δ on a simply-supported beam. Here, a transverse distributed load ω correlates with elastic bending-stiffness properties KE to induce vertical displacement δ. An additional flexural contribution comes from the relationship between this deformed configuration and axial loading P. The geometric stiffness properties KG which dictate this relationship are discussed further in the P-∆ implementation article. Values for maximum flexural response, which occurs at element midspan, are shown in Figure 1:
Figure 1 - P-δ applied to a simply-supported beam