Solid Edge How to get the correct Mass Properties for a part with non-solid geometry

A customer needs obtain the Mass Properties and the Center of Gravity for a parachute canopy that has an approximate length of 25 m, a width of about 8,5 m and a thickness of about 0,1mm, with a given density of 800 kg/m³ . The customer's estimated Mass for the parachute was under 100 kg, however in the Solid Edge Part environment the Physical Properties result in a mass of about 500 kg - which is far too much.  Also the Center of Gravity is several meters away from the area where it would be expected.

Solution

Due to the non-standard relationships of length, width and height ( 25000,8500, 0.1)  the system is calculating with an unsatisfactory accuracy.

The default accuracy within Solid Edge Part is set to 0,99 in a bandwidth between 0 and 1 - this accuracy is absolutely sufficient for solid geometry models that have a "standard" relationship in length, width and height.

In this case there is a big discrepancy between length and height with a factor of 250000, and this causes a wrong calculation with that accuracy.

Setting the accuracy from 0,99 to 1 will result in a mass calculation of 72 kg - which is far closer to the customer's estimate.  Additionally, the Center of Gravity appears in the expected area.

The reason, why the accuracy is not set to 1 per default, is that setting the calculation at the highest value would result in a high level of CPU power, which for most bodies this is not needed - therefore the setting of 0,99.

As an example, refer to the table below with specific thickness ( = height) and modified accuracy for that model:

Hardware/Software Configuration

Platform: INTL64
OS: windows
OS Version: n/a
Product: SOLID_EDGE
Application: PART/SHEETMETAL
Function: TOOLS

Ref: 002-8016819