The Analysis Of Fatigue Characteristics For Prestressed Boom Structure Of Dynamic Compactor

As a special equipment for ground handing, compaction machine is widely used in all kinds of foundation reinforcement construction. Dynamic compactor has sharply high load factor, sudden unloading, frequent operations and other working characteristics. Compared with the ordinary cranes, the working grades is higher. Despite some improvement measures have been adopted in the structural design, it occurs frequently that dangerous positions on the boom have fatigue failure ahead of time, because the boom suffers alternating load. Therefore, it is necessary to study how to improve fatigue resistance. This article will design prestressed boom structure based on prestress technology to improve the fatigue resistance of boom.In this paper the CGE400dynamic compactor was taken as the research object, which was developed by Construction Machinery Institute of Dalian University of Technology. Firstly, software ANSYS/FE-SAFE is used for analyzing the fatigue strength of the original boom to find the positon where the fatigue is lowest. According to crane design specification, the fatigue strength of the original boom is checked, and then identify the hazardous area where fatigue strength is not enough. Then, based on prestress technology, a prestressed boom structure is designed. And fatigue life of the original boom, the prestressed boom, and the original boom with the thickness of the chords increased is analyzed. Finally, comparison on the stiffness of the prestressed boom and the original boom is made according to deformations under loading obtained by using software ANSYS. In addition, instead of original pinned connector, a new connector for boom is designed to reduce the weight increased by prestressed pulling boards.Fatigue analysis showed alternating stress brought out by sudden unloading can cause fatigue damage on the boom, and fatigue resistance of the boom can increase by means of appropriate prestress added on the boom. New connector ensure the bear capability needed for boom while reducing the weight.Prestress technology was applied to the boom of Dynamic compactor is put forward for the first time in this paper, which is a meaningful attempt. Research methods and ideas can provide reference for the study of prestressed structures which is in the similar field of construction machinery.