Damping System Based On The Fm Tone Moment Vibratory Hammer Mechanical Dynamic Analysis

As the development of Foundation Construction, every kind of large constructions putsforward new problems to the development of foundation. Comparing with the other kinds offoundation machines, pile foundation can bear larger load, be operated conveniently, and bemechanized much easier. So now pile foundation is applied much widely, and developed morerapid.As the development of technology, especially the technology of vibration, these make theapplication and development of vibratory pile hammer be much better, and make it the majoritymachine of pile work. But in the procedure of working, vibratory hammer often happensaccidents, makes the program stop or become slower. So needs to do some deep research aboutthe vibratory system of vibratory hammer, and it will offer theory data to the design of machineand its work .this thesis summarizes and analyzes the development of vibratory pile hammer both hereand abroad, indicates that vibratory pile hammer with hydraulic is the trend of developing. Thisthesis makes analysis about the basic structure to the system of vibratory pile hammer, andmakes it sure that it needs to do some research to the system of reducing vibration.Based on the hydraulic vibration theory, this thesis does elaborate analysis by adding thestructure of modulating moment, amplitude, frequency and the system of reducing vibration.Study shows that it is quite important for center of excitation force to inosculate with theplane bary center of vibratory hammer and the geometry center of vibratory hammer's dampersystem, otherwise, the force inflicted on each helix spring increases to two times and thesituation of springs are different. All of these will arouse the unsteady working for vibratoryhammer. So it must be have great regard for. In this thesis, the finite element stress, strain anddisplacement of each kind of helix spring used in vibratory hammer are calculated and analyzed.The maximum of load and distortion appear at the mutation part near the load position. It is bestto using the springs with shape of equal diameters or that of column in the middle and taper attwo ends. The stress inside the steel wire section of spring is greater than that outside beingseen from lateral excursion, and the condition of section's load variation is a main reason whichis apt to bring fatigue and damage.Seen from the distortion analysis of springs, the spring used in damper system of vibratoryhammer should be with partnership on left and right because of the uniformity and easyexcursion of load endurance for helix spring, otherwise, producing polarization of vibratoryhammer.In this thesis, to eliminate the shortcomings, weak load endurance and too large distortion,embedding metal board into helix spring can make the rubber chip thin, increasing the shapecoefficient of the chip. Then the detailed analysis is done. In fact, this method is feasible andeffective.The thesis finally points out that the trend of the development of vibratory hammer is highfrequency, super high frequency;adopting stepless changing moment to realize the controlsystem of mechanical-electrical integration, intelligent working;developing to reduce noisesand vibration, and improve the dependability of working and the capability of high power andfrequency vibrator's bearing vibration;and improve high speed drive machines' lubricate. Thekey is the research to middle or high frequent vibrations' influence on characteristic of soil andtechniques of construction.