Papers by Keyword: Unload

Abstract: The experimental study of unload on temperature characteristics is put up for heavy vehicle hydraulic retarder, forms the retarder unload testing method of temperature characteristics, confirms the relationship between the temperature of hydraulic retarder inner cavity and unload torquecavity air density, which can be used to instruct the simulation of retarder inside flow field in unload condition and actualize method to reduce air losing, and it lays the foundation for developing mechanism research to reduce air losing of retarder.

Abstract: Based on the elastic-creep theory, a series of expressions that describe stress-strain increment and corresponding recurrence formula of reinforcement and concrete are derived from some basic formulas for eccentric compression RC columns. The stress-strains changing process considering repeated loading is calculated through numerical method. The effect of a long-time load on creep behavior of eccentric compression RC columns and stress process after unloading are studied. Many factors are considered in the study, which includes the eccentricity, the reinforcement ratio, the loading age and the duration of loading. Adopting this methodology may simplify the complexity of creep analyses and provide some references for the design of the structures.

Abstract: Combined with construction of large span steel truss in the bottom of an Archaized tower, stresses in key members, displacements in control nodes and temperature variation were monitored and measured before and after moving construction temporary constraints. The unloading process based on the rule which constraints were unloaded gradually from outer to inner and four steps were carried out in the field. Compared with measured and theoretical results, they can meet with each other perfectly. The mechanical sensibility of steel stresses with temperature changing were also revealed. Then the reasonable conditions of unloading for the steel truss were advised. The process and method given in this paper provides the basis for safely construction of the Archaized tower, which would be reference for similar load bearing transform of steel structrues.

Abstract: The transient time of the clutch disengagement is of key importance, as far as controlling performance of clutch screw presses is concerned. Therefore the hydraulic unloading of the clutch for a screw press has been analyzed, by which three schemes of poppets were compared based on calculation and simulation. Thereafter we found it is the widely used mode of ‘pilot-main poppet valve’ that had much advantage. At the same time the paper can provide an analysis method and be as the instantiation references for the design of such systems.