We knewd that in Algor we simulate the joints or pin by Truss element.
My question is if I creat a pin by the truss elements
What the mass density of truss use for?
II fouond that the mass of pin(created by truss element) has the relation with section area and the number of truss.
So what is the exact definition of mass density of the pin?
I am not entirely clear what you are asking or the reason you are asking. Just like any part, the mass equals (the volume of the elements) times (the mass density). For of a part made from truss elements, the mass equals (the total length of all elements x cross-section area) times (the mass density). If performing a modal analysis, the mass affects the frequency. If performing a linear stress analysis and gravity is applied, the weight causes a load. And so on.
If you do not want the pin to have any mass, then set the mass density to 0.
Let us know if you have any other questions.
Simulation Mechanical user since Dec 1997