Effect of Rigid Links Young’s Modulus on Turbo-Generator Foundation FE Dynamic Analysis

Turbo Generator foundation is one of the Paramount structures; if not the most one; in power generation plants. For the Turbo Generator foundation design, finite element (FE) is the commonly acknowledged analysis tool in structural engineering field. As the turbine and generator are relatively rigid compared either to the foundation or to the soil in analysis, both machines contributes in the finite element model through their masses applied at their center of gravity. Those elevated masses are connected to the foundation using rigid links / rigid beam elements in order to transfer loads / masses from the machines CG level to the foundation level. Rigid links are usually simulated in the analysis model as beam elements with a large Young’s modulus value relative to other elements presented in the model (e.g., 100 times stiffer than the elements they are linked to) [1].  The aim of this paper is to examine study and recommend the most efficient rigid links Young’s modulus value and modeling method in order to simulate the actual behavior of the system to reach the optimum dynamic and static analysis results of the Turbo Generator foundation. the analysis result indicates that using Young’s modulus for the rigid link equal to ten-thousand-time steel young’s modulus provide the most realistic dynamic behavior for the machine foundation.