Determinación y solución a los fallos estructurales en un autobús urbano

Abstract

The origin of an automotive structural mechanical failure 
can be originated by diverse causes, due for example to 
the structural geometry, the materials of manufacture, the 
processes of manufacture and the mechanical loads, that 
appear during the time of service for the that were designed, 
among other causes. The determination of the mechanical 
causes that provoke such failures is not a simple task, so 
it is recommended to apply systematic methods that allow 
identifying and characterizing them efficiently. Currently, there 
are experimental and computational tools, which can be used 
of an integral way to assess failures, locate them and give them 
a practical solution.
In this article an efficient method is presented, which was used 
to identify and quantify the causes that originated mechanical 
structural failures (generated by cracks) in a bus. Through a 
numerical method, was searched for and found the solution 
to the problem, which was implemented and evaluated. The 
method integrates experimental and numerical tools for the 
analysis of stresses and deformations (photoelasticity and 
electrical extensometry) required for the study of failures. 
Static tests (torsion and flexion) and braking, curving and 
travel tests were carried out, with the purpose of obtaining 
data of stresses and strains that would allow evaluating the 
mechanical conditions of the bus. The load conditions of the 
tests were a Gross Vehicle Weight (PBV) and PBV + 20%. To 
carry out the road tests, only the information of the edges and 
potholes was considered, since they turned out to be the events 
that caused the highest levels of stress.
The study was carried out on a prototype bus, which did not 
present structural mechanical failures. The case study presented 
in this paper refers to finding the causes and the solution to a 
problem of a failure by a fissure located on the floor of a bus.
Finally, the results obtained show the efficiency of the proposed 
analysis method as well as the integration of the experimental 
and numerical tools used, in a systematic and integral way 
identifying the causes that originated a failure in the structure 
of the bus.