The hi-Cr white cast iron for working under the severe repetitive-impact abrasion condition should be heat treated to obtain martensitic matrix with only few of residual austenite, that would increase its impact-spalling resistance.

A 3-D FE model was established in order to investigate dynamic responses of the round PCB and find the weakness of solder joint in packaging under drop impact.

With increase in electronic package density,the reliability of a board-level package under drop impact load becomes a key issue.

Drop direction is an important parameter of drop impact,this paper presented a new method to measure drop direction and introduced the basic structure,measurement circuit and principle of the sensor.

This paper began with an experiment of drop hammer impact crushing on glass balls by using drop hammer test installation.

An analysis is made on the cracks formed on the grinding mill cylinders and the fatigue failure is considered to be a main cause and also, the falling impact of some big blocks will somehow damage the grinding mill cylinders.

A non-linear parameter is modeled by experiment applying NLAR method through displacement,which comes from acceleration of the dropping shock to EPE by integral,and the exactitude of the model is verified by applying the numerical method,the results show that the model depicts the dynamic course of extruded polyethylene(EPE) dropping impact exactly.

The major mechanical damages of fruit are usually not direct split but local bruise caused by dropping impact during harvesting, sorting, packaging, and transportation.

For the viscoelastic products such as fruits,the major mechanical damages usually are not direct split but local bruise caused by dropping impact during distribution,packaging and transportation.