dgkhan - In a wood framed structure, a common collector element would be a typical floor framing member that is designed for the axial load induced by the unit shear in the collector element. Check out Breyer's book for some good examples, but you can calculate the tensile force in the collector by applying the unit shear multiplied by the length of the collector. Remember, you will be dragging the load from both diaphragms through the same collector element.