Finite Element Analysis of Cylinder Piston Impact Based on ANSYS/LS-DYNA

Nonlinear dynamic finite element analysis system ANSYS/LS-DYNA is used to analyze the characteristics of cylinder piston impacts to meet the requirements of safety and stability for cylinder. Based on the fundamental theories of explicit dynamics, a finite element impact model of cylinder piston was established. The impact force variation, the piston surface stress distribution and the relationship between maximum impact force and different piston initial impact velocity were estimated by numerical simulation. The results indicate that the impact force on the force transducer is about 81% of that on the cylinder piston owing to the collar between the piston and the force transducer, and the stress, close to the surface center of the piston, is larger than that of other areas. The results also show that different initial impact velocity don’t affect impact time but only the impact force, and the maximum impact force is proportional to the initial impact velocity. Keywordscylinder piston; explicit dynamics; finite element; impact force; stress