Romuald Bertolaso

Abstract

Numerical and experimental study of the load distribution in a balls screw system

Romuald Bertolaso - 24 June 2010

With the expansion and diversification of the application of the ballscrew in recent years, there is a strong demand for this system which has better functionality thanks to a large mechanical efficiency and high power transmission. Screw ball of this study is part of the horizontal actuators (THSA) aircraft. The mobility function of the rear is provided by moving a nut along the screw through a system recirculating ball. The work presented in this paper concerns the study of the load distribution in the volume for ballscrews systems It is to develop a finite element model for assessing the distribution of constraints in order to calculate the lifetime of these elements and optimize the system. After defining the characteristics of a ballscrew, an experimental approach was carried out in parallel a study of finite element simulation to validate assumptions for different models.
Measuring Method used to highlight the load distribution in the volume is photoelasticity. In terms of applications, 2D photoelasticity will be used for experimental analysis of mechanical behavior of ball screws and simplified photoelastic 3D optical sectioning for a bearing ball model.
The numerical elements validation is studied done by comparing the results obtained experimentally and by numerical calculations. More specifically, the comparison is between photoelastic experimental fringes and fringes numerical calculated after post-processing of simulations. The conditions limits and validated the result simulations that were quantitative and qualitative become. The next step is coupling of these qualitative results in a fatigue model to calculate the lifetime of the models studied.

Last modified: 12/10/2010 05:09 PM