8-18HY bend walking beam pumping unit so as to increase the load on polished rod capacity of maximum stroke through the optimized main technical parameters.

In the model, the total moment of the composite beam with interface slip consists of the local moment carried by superposition beam with free interface slip and the global moment carried by the composite beam without interface slip.

In the model an assumption was made that the total moment of a composite beam with interface slip was consisted of a global moment that was borne by a composite beam without interface slip and a local moment that was borne by a superposition beam with freely interface slip only.

Recently, although some analytical solutions and a numerical solution based upon the theory of flexible shells were proposed to solve the bellows overall bending problems, it is still necessary to develop other methods to examine and reinforce the sol.

When the differential settlement occurs, some buildings are likely to crack, for example, the masonry structure with high length to height ratio will crack due to overall bending stress, and crack will also be caused by stress concentration where rigidity changed suddenly in the masonry structure with discontinues longitudinal rigidity.

The bended walking beam pumping unit has problem of complex fabrication process,long production cycle and low efficiency.

Aiming at the measurement of resistance of ZFS6800/18/35 support with integrated roof timber in 300 m super-long fully mechanized sublevel coal caving working, this paper analysed distributing character of support resistance and the reason why the front legs resistance is bigger than the back legs'.

Fracture characteristics of wingbeam integrated structure was studied in this paper.