My former manager used to say: “dig where you stand” when I was trying to improve the entire company’s processes. He meant that I had more impact focusing on the things I’m responsible for rather than trying to change everything everywhere.
We applied the same philosophy to an existing gap in heavy equipment system simulation world: the digging force estimation. Historically, we used to rely on Discrete Element Modeling or customer’s in-house code to apply digging forces to the Simcenter Amesim’s model.
This is no longer needed since Simcenter Amesim 2019.2 features a digging force model based on Fundamental Earth Moving Equations.
Simcenter Amesim digging force models
This model allows to apply forces to the bucket and understand its impact on the pistons chamber pressures and on the entire system.
Thanks to digging forces calculations, you can assess dug volume for different soil properties (rocks, sand …) and on different topological configurations.
Simcenter Amesim digging force results for different ground inclinations
As an example, we could optimize the bucket size. Oversizing the bucket will cause extra load, swing, and dump times and extra machine heat when the operator is stalling the bucket. When using an oversized bucket, the machine becomes tippy and the operator will restrain from full bucket loads.
So, the extra weight of bucket becomes a boat anchor hanging on the end of the arm rather than an advantage. We can do a batch run with different buckets capacities and weights and find an optimum for a given bucket. Indeed, if the bucket is oversized, the cycle time increases drastically compared to the increased quantity of dig soil.
Overall, you will be able to perform trade-off studies between ideal productivity and fuel consumption. That is a great step forward in the digital twin for heavy equipment journey!