1. User Defined Element Enables modeling of user defined element using an external dll. The external dll estimates the forces, stiffness and damping. 1.1. Input Path and filename to the dll Specification the connection between user defined elements and element end or series of elements ends. The user defined element can be connected to end, two or both. Input file for user defined element 1.2. External dll interfaces The external dll must contains five functions with names userdef_files_init() userdef_element_init() userdef_element_calculate() userdef_element_finish() userdef_files_finish() Description of the input and the interface for the external userdefined element is given in User defined element. HAWC2 Import Interface Userderdef_element_init()