Redundant and force-differentiated systems in engineering and nature

Sophisticated load-carrying structures, in nature as well as man-made, share some common properties. A clear differentiation of tension, compression and shear is in nature primarily manifested in the properties of materials adapted to the efforts, whereas they in engineering are distributed on different components. For stability and failure safety, redundancy on different levels is also commonly used. The paper aims at collecting and expanding previous methods for the computational treatment of redundant and force-differentiated systems. A common notation is sought, giving and developing criteria for describing the diverse problems from a common structural mechanical viewpoint. From this, new criteria for the existence of solutions, and a method for treatment of targeted dynamic solutions are developed. Added aspects to previously described examples aim at emphasizing similarities and differences between engineering and nature, in the forms of a tension truss structure and the human musculoskeletal system.