5. notes

5.1. Length of discrete elements

For discrete elements whose support mesh is an element with two nodes SEG2, the length of the element does not intervene in the response of the element, except for the DIS_CHOC law of behavior. Indeed, for the other laws of behavior, the relationship is expressed as a function of the relative movements of the two nodes. For law DIS_CHOC, the length of the element is involved in determining the state of contact or detachment by comparing the movement of the nodes as a function of the length of the element and the values DIST_1 and DIST_2.

5.2. Transmission of efforts

There is no transmission of the moment linked to a power torque. This limitation is illustrated in the case where a displacement DY is imposed between two nodes of a discrete element DIS_TR or DIS_T. The two nodal reaction forces FY are equal and opposite but this pair does not generate moments for case DIS_T and for case DIS_TR if the coupling terms (translation-rotation) are assumed to be zero.

For discrete elements of great length, it is therefore possible to find a global balance of unwanted moments.

Fig. 5.1 Transmission of efforts.