Experimental Study On Damping Properties Of Fiber Reinforced Concrete Large Deformation

In the design of concrete structure, damping in the calculation is generaly select the standard constant of5%, but at home and abroad have a large number of experiments show that the building process of force damping values of constants are not reasonable, so the concrete at different deformation stages of the damping value research is ver\important, as the fiber concrete penetration rate increasing, the fiber concrete material damping value research is very necessary.This paper studies the different fiber polypropylene fiber concrete constitutive relation curves, the hammering method on liber concrete in different residual deformation damping values were measured, and using the phase difference method for the different state of stress in the fiber concrete damping measurement. Summarize the condition of small deformation of the damping value varies with the strain variation law, and find the fiber concrete bearing condition of large deformation, the damping value varies with the strain variation trend.The fiber concrete damping measurement method and the damping and the relationship between the strain, the main need to do the following work:(1) Fiber concrete research, mainly is the liber concrete strength and ultimate strain and its study of the constitutive relation.(2) Damping measurement method research, by hammering method on fiber concrete in small deformation case damping values are measured, to find out the condition of small deformation and strain the relationship between damping, damping between fiber content and relationship.(3) Further using phase difference method for damping and the relationship between the strain of.Measure the condition of large deformation of liber concrete damping, reorganizes analyzes damping and the relationship between the strain.In this paper, the main innovation is, developed a new damping test method to measure test block damping, damping and measured with strain change trend.The new method is to use the test block under external low frequency vibration load, the signal acquisition equipment and acquisition of stress-strain-time and time signal curve analysis, damping values, compared with hammering method measuring damping method has the following advantages:(1) From large sample size limits, this method can be used in the larger size of the concrete component, simple test method, computational analysis can also be done directly in the software.(2) Is not affected by the loading system to restrict, the acquisition of stress strain method is not restricted by the loading device to restrict, so can be used to measure the test piece bearing state under different strain of damping value.(3) The test is simple, general sensor signal acquisition can be affected by many outside interference, phase difference method is direct acquisition of material itself and the stress and strain, not by outside excessive effect, so that the influence on the measuring results.