Study On Static And Dynamic Properties And Damage Mechanism Of Steel Fiber Polymer Concrete Machine Tool Structural Elements

It is significant in theory and practice to study on manufacturing machinetool structural elements with excellent static and dynamic properties by usingnew material for improving machining quality and the whole mechanicalmanufacturing industry standard. In this thesis, the static and dynamicproperties and damage mechanism of a new material, steel-fiber polymerconcrete (SFPC) are studied. Then we research it's using in machine toolstructural elements so as to improve the static and dynamic properties ofmachine to satisfy the needs of development of machine to the direction of highaccuracy, heavy cutting and high efficiency. The main researches and theirresults are listed as follow:The effects of SFPC components and it's content on it's static and dynamicproperties are studied by experimental testing ,and theory analysis methods. Onthe base of these results, we decide the best SFPC components and their contentfor manufacturing machine tool structural elements.The forming mechanism,mechanical behavior of interphase and steel fiberreinforcing mechanism are studied by using micromechanics theory of composite.Some of mathematical models, such as tensile stress of steel fiber, shear stress ,stick coefficient of interphase strength and elastic modulus of SFPC areestablished. Therefore, we can draw the conclusions bellow: The first, we shouldtry our best to make stick coefficient to be 1 by selecting appropriate ratio oflength to radio of steel-fiber. The second, we should strengthen interphasestrength. in order to use steel-fiber's strength amply. The third, strengthening PCstrength, we can preparation high strength polymer concrete, matrix, too. Whenthe interphase strength is enough, using high strength steel fiber can bringdistinct efficiency.Constitutive model with damage of SFPC is established by using damagemechanics theory, and it is proved correct by comparing with testing dates.The influence of steel fiber on damping of SFPC is studied by complexdamping theory and free vibration method, and the mechanics of damping isexplained from microcstructure. When steel fiber content is less, the damping ofSFPC can be or even higher than the damping of PC ,it is about 7 times as muchas damping of iron.Production process of SFPC machine tool structural elements is studied.Comparing with iron machine tool structural elements, SFPC can be formed inroom temperature, needn't melting heating and ageing. Therefore, theproduction process manufacturing SFPC machine tool structural elements issimple, easy to realizing mechanization and automation so as to improve workingcondition ,decrease environment pollution and save a lot of energy sources andiron.Analyzing deforming and influences of them on machining accuracy ofSFPC machine tool structural elements and PC machine tool structural elementswith same form and size, loaded on static force. Thus a conclusion can be drownthat the SFPC's static properties is superior to PC's .Modal analysis and harmony response analysis on SFPC machine toolstructural elements and PC machine tool structural elements have been carriedout by using finite element modeling and simulation as well as excitation. Itshows that the dynamic property of SFPC machine tool structural elements issuperior to iron machine tool structural elements further.Summarizing all above, we can conclude that machine tool structuralelements made in SFPC is superior to that one in PC in static property, and issuperior to that one in iron in dynamic property.