Modeling notes: material non-linearity was also included in the analysis strategy to better understand the elastic-plastic deformation response of the Nylon 66 throttle pedal.
Nonlinear finite element analysis of plastic throttle pedal assembly involving extensive contact behavior between the pedal arm, body, and cover plate. These high-strength plastic parts were rigorously evaluated to optimize the design for extreme durability.
Figure 1: Femap model showing solid 10-node tetrahedral elements were used for the body and pedal structures. The cover plate was modeled using three-node plate elements. The choice of these three-node elements was required to facilitate the match up of grid patterns between the body and cover where gap and rigid elements (Nastran RBE2) were connected. Although three-node plate elements are exceeding stiff, a very high mesh density was used to correct for this deficiency. The cover was modeled as 2.54 mm thick.
Figure 2: A very simple constraint set is used in this analysis. The pin attachment bolt (upper part of the body) is fixed to simulate its contact with the base. At the lower sliding connection, a small chunk of plastic is used to enforce contact (gap elements on all sides) between the body and base.
Figure 3: Nastran deflection results on Nylon 66 all-plastic pedal assembly
Figure 4: Nastran nonlinear stress results contoured over the Nylon 66 accelerometer pedal assembly