PASSENGER CAR BODY STIFFENING

Methods for ensuring the required stiffness of passenger car bodies are viewed, making it possible to identify the main de-sign solutions and the technology of their assembly. Alternate designs of stiffening carriage frame with additional elements, using one and two cross ridge partitions, as well as a model with two partitions connected by longitudinal elements were obtained. The lowest bending vibrations frequency, maximum stresses acting in the frame stiffening zone, as well as the mass penalty due to the introduction of additional elements were adopted as the criterion for choosing a rational constructive solution for stiffening supporting structures. The effectiveness analysis of the proposed constructive solutions is carried out within the framework of the accepted criteria using the finite element method. It was found that the most optimal way for body stiffening is a model with two load-bearing partitions interconnected by longitudinal elements. This alternate design renders possible, with a slight increase in body weight, to increase body stiffness up to 8,92 Hz and reduce the maximum stresses acting in the amplification zones to 167,2 MPa. It has been found that stiffening owing to two load-bearing parti-tions interconnected by longitudinal elements, is effective and workable, therefore it is recommended for further new designs of passenger car bodies. In this regard, the technological process of assembling the body with a strengthen design has been developed and its assembly design project is presented. It is found that the change in the process operation of the passenger car body production due to new elements do not require the additional production lines, since assembly can be performed using the equipment available on the existing production line. It is recommended to use a portal contact point machine with a double inlet current supply in the process operation, which will ensure the quality of the assembly process.

passenger car body, supporting structure, stiffness properties, natural frequency of bending vibrations, process operation