Research On Bucket Structure Optimization Of Impact Excavator For Frozen Soil

China has the wide distribution area of frozen soil. As constructions are increasingly frequent in cold regions consequently, the problem of frozen soil excavation is more widespread. However, the strength of frozen soil much stronger than unfrozen soil that the difficulty of frozen soil excavation is increased, which has been the technical problem that persecuted engineering operations in cold regions. It is necessary to carrying out the research on crushing characteristics、 excavation method and excavation equipment optimization of frozen soil, thus improving the frozen soil excavation technology.This article reviews the research status and progress of frozen soil excavation and gives a general introduction to the SHPB test technology, the finite element theory and numerical simulation method. Moreover, by combining the experiment , which in the existing references, with numerical simulation, Getting the parameters of the constitutive model H-J-C that Suitable for frozen soils. Then based on this model, and using the finite element dynamic analysis software to simulate the damage process of frozen soils under high speed impact. We obtain the following conclusions:(1)Through simulating the SHPB test of permafrost, it is found that results of numerical simulation were better conformed to experimental results, especially the trends of stress-strain curves, so it is feasible to use large-scale finite element software to simulate the impact test of frozen soils. And by this simulation, we obtained the parameters of permafrost H-J-C model.(2) Based on the above model parameters, we simulate the process of wedge tools vertical impact frozen soils. Under the same velocity, wedge cutters are more easily broken permafrost than cubic cutters, the sharper cutter is, the more easily it penetrates into permafrost. But not the wedge angle is smaller, the effect is better. There is a best wedge angle of about 45° to break permafrost. So the wedge angle of mechanical excavator’s punch designed about 45° is more reasonable when breaking permafrost.(3) Simulating wedge punch of 45° impact permafrost with different incident Angles, the results showed that cutters had been rebound by soils. The rebound phenomenon is more obvious, the less kinetic energy be used to destroy permafrost, the more additional energy consumed, and it is unfavorable to break permafrost. When incident angle is about 30° or 60°, the damage of frozen soils is the largest. However, when incident angle is 45°, the damage is the least. Therefore, when impacting and crushing permafrost, incident angle should be chosen about 30° or 60°, that can consumed less energy and the effect is better.