Abstract: Non-linear FEM calculations are indispensable when
important technical information like operating performance of a
rubber component is desired. For example rubber bumpers built into
air-spring structures may undergo large deformations under load,
which in itself shows non-linear behavior. The changing contact
range between the parts and the incompressibility of the rubber
increases this non-linear behavior further. The material
characterization of an elastomeric component is also a demanding
engineering task.
The shape optimization problem of rubber parts led to the study of
FEM based calculation processes. This type of problems was posed
and investigated by several authors. In this paper the time demand of
certain calculation methods are studied and the possibilities of time
reduction is presented.
Abstract: Non-linear FEM calculations are indispensable when important technical information like operating performance of a rubber component is desired. Rubber bumpers built into air-spring structures may undergo large deformations under load, which in itself shows non-linear behavior. The changing contact range between the parts and the incompressibility of the rubber increases this non-linear behavior further. The material characterization of an elastomeric component is also a demanding engineering task. In this paper a comprehensive investigation is introduced including laboratory measurements, mesh density analysis and complex finite element simulations to obtain the load-displacement curve of the chosen rubber bumper. Contact and friction effects are also taken into consideration. The aim of this research is to elaborate a FEM model which is accurate and competitive for a future shape optimization task.
Abstract: The present work presents a method of calculating the
ductility of rectangular sections of beams considering nonlinear
behavior of concrete and steel. This calculation procedure allows us
to trace the curvature of the section according to the bending
moment, and consequently deduce ductility. It also allowed us to
study the various parameters that affect the value of the ductility. A
comparison of the effect of maximum rates of tension steel, adopted
by the codes, ACI [1], EC8 [2] and RPA [3] on the value of the
ductility was made. It was concluded that the maximum rate of steels
permitted by the ACI [1] codes and RPA [3] are almost similar in
their effect on the ductility and too high. Therefore, the ductility
mobilized in case of an earthquake is low, the inverse of code EC8
[2]. Recommendations have been made in this direction.