A New Method Of Prestressing,Its Manufacturing Method And Engineering Applications

A new method of prestressing is proposed in this thesis, with the main objective of illustrating its manufacturing method and demonstrating its potential application in engineering. The principle of this new method is to pre-store residual strain in the preload stress tendon. The process of applying prestress is that raising the temperature of the tendon to some degree until the inside compressed material or adhesion agent get soften, thus, generating a significant strength-difference between the inside compressed and outside tensile material. The tensile material elastically shortens in this case and releases the pre-stored residual strain energy purposefully to the reinforced structure, which realizes the prestressing technology.This thesis consists of six chapters:The first chapter gives a literature review of the prestressing technology, the high-temperature resistance of ceramic matrix and carbon matrix composite materials and the oxidation resistance of carbon fiber in high temperature. The main content of this thesis is also presented.The second explores one kind of crack-free coating fiber and its manufacturing method. Simple theoretical analysis and numerical calculations are applied to optimize the design.In the third chapter, a kind of pre-stored stress composite tendon reinforced ceramic matrix composite material is introduced and its manufacturing method is shown in detail. This kind of pre-stored stress composite tendon provides prestress to the ceramic matrix target by anchoring remove of the tendon itself.The fourth chapter presents one kind of pre-stored stress tendon reinforced composite material. Its manufacturing method is also introduced.The fifth chapterchapter introduces one kind of pre-stored stress tendon with a composite structure. This kind of tendon is designed to provide prestress to the target, with the capability of storing prestress and controlling the release of prestress. The manufacturing method of this kind of tendon and its prestress release technology are also presented.The sixth chapter provides the conclusions on the new method of prestressing. This series of patents are feasible in theory, but their practical applications are not ensured now without experimental studies. Therefore, further research work need to be done.