Tendons modeled as loads

(1) Calculate tendon loads, e.g. loads acting along the tendon that the tendon is exerting on the rest of the structure. When losses are specified, they are also included in the calculated tendon forces.

(2) Based on the tendon discretization, the program breaks the tendon into smaller pieces (discretization segments) and determines forces (distributed and concentrated) acting on each discretization segment.

(3) The program looks at each discretization segment and determines whether it falls within a bounding box. If the discretization segment falls within the bounding box, the tendon loads for the particular discretization segment are statically transformed and applied to the joints of any bounding object. In this discussion, a bounding object is the bounding box of any object in the group specified to be loaded by the tendon.

Tendons modeled as elements

(1) Calculate tendon loads exactly the same way as for tendons modeled by loads.

(2) Based on the tendon discretization, the program breaks the tendon into small discretization segments. If any discretization point (i.e., either end of the tendon piece or discretization segment) falls within the bounding box of an element, that point is connected by an interpolation constraint to all joints of that element. This means that for large discretizations, the tendon may not actually be connected to every element through which it passes.

(3) Based on the tendon loads calculated in step 1, the program determines and applies axial strain (s11) to each discretization segment. For tendons modeled as elements, the tension at each end of a tendon object is converted to an equivalent strain, and applied as a strain load to the tendon object. This does not depend on whether the tendon is contained in a bounding object or not.

Tips

• You can use Display > Show Load > Tendons > Show calculated values… to see the loads that have been calculated along the length of a tendon due to the specified tension and losses.