Referring to an egg shaped yield function for geotechnical materials, a failure criterion for light-weight aggregate concrete is put forward, in which the tensile and compressive meridians are egg shaped curves and the failure envelopes in deviated plane is smooth elliptic curves. The suggested failure criteria could describe the failure characteristic of lightweight aggregate concrete at different stress state. The precision of the suggested egg shaped failure criteria is verified by comparing with experiment data of lightweight aggregate concrete.

This paper introduces the working principle of power system on tracked vehicles. Tracked vehicles with high pressure air or pulling the battery starts, due to the main power supply system power supply, can't fight. Through an analysis on the failure of electricity generation of the main power system, a tachometer sensor is designed and used as main power providing excitation and causing an electric potential difference, which realizes passive power supply after non-battery starting.

To coat with much of lubricating grease is an effective approach to slow down the wearing and rusting trend of each mechanism, the lubricating grease must be removed before grease-change maintenance and overhauling of the artillery. At present, the grease removing methods mainly include physical heating, mechanical removal, chemical cleaning, etc. Comparing the advantages and disadvantages of various methods, this paper proposes to use the technology of a high-pressure water jet cleaning. This method overcomes the problems in the process of grease removal.