New substrates of roof membranes, such as regid plastic foams and gas concrete planks have promoted membrane failures from fatigue rupture, because of their relatively large joint movements. The ability to withstand these larger movements, therefore, has been recognized as an ever more important property for roof membranes. This paper deals with a mathematical treatment of strains induced in asphalt felts, reinforcing components, in multi-ply membranes caused by joint movement in substrate. Being based on the theory of elasticity, felt strains in multi-ply membranes are analyzed by means of an electronic computer for solving simultaneous differential equations. The strains in fully bonded membranes are analyzed at first, and modifying the boundary conditions, strain increases in the surviving felts are investigated in cases that some of felts rupture. The effect of installation method of loosely laying membranes over joints in substrates is also cleared by solving two simultaneous differential equations for the bonded and loosened parts so as to satisfy the boundary and serial conditions. The equivalent model by simplified finite element method is investigated in order to treat felt strains by the stiffness method.
|Number of pages||33|
|Journal||Telcom Report (English Edition)|
|Publication status||Published - Jan 1 1978|
All Science Journal Classification (ASJC) codes
- Hardware and Architecture
- Electrical and Electronic Engineering