The ability to predict the durability of a structure depends on the knowledge of
operating loads experienced by the structure. Typically, multi-body dynamics
(MBD) models are used to cascade measured wheel loads to hard points. However,
in this approach, there are many sources by which errors creep into cascaded
forces. Any attempt to reduce sources of such errors is time consuming and
costly. In typical program development timelines, it is very difficult to
accommodate such model calibration efforts. Commercial load cells exist in the
industry to give engineers insight into understanding the complex real-world
loading of their structures. A significant limitation to the use of load cells
is that the structure needs to be modified to accept the load cell, and not all
desired loading degrees of freedom (DOFs) can be measured. One of the innovative
solutions to calculate operating loads is to convert the structure itself into
its own load transducer. The D-optimal algorithm along with the pseudo-inverse
technique provides a theoretically sound and versatile method to identify
optimum positions and locations to place the sensors (i.e., strain gauges) on
the structure where its response is to be measured. A pre-calculated calibration
matrix through pseudo-inverse is then used along with measured responses to
reverse calculate loads acting on the structure. The accuracy of calculated
loads with this approach is typically high compared with conventional load
cascading methods as sources of errors are less in this method.
This work is focused on load reconstruction, FE analysis, and lightweighting of
the bell crank lever of a commercial vehicle. Practical difficulties associated
with the load reconstruction method and solutions are also discussed in this
research paper.
