Finite element analysis and optimization of multi-layer combined ultrahigh pressure cylinder
The finite element model was established by the finite element method of Workbench. The prestressed state and the working state of the multi-layer composite cylinder was used to calculate by the finite element method. The general distribution law of the stress of the multi-layer cylinder is obtained, and the equivalent stress distribution is not uniform. At the same time theoretically based on the elastic limit of multilayer composite cylinder unified solution, and the optimization condition is determined. The design of multi-layer ultrahigh pressure cylinder is optimized. The results show that the nonuniformity of the stress distribution of the cylinder can be improved greatly. The study can provide technical support for the structural design and optimization of the multi-layer ultrahigh pressure cylinder.
Research on Impact Stress and Fatigue Simulation of a New Down-to-the-Hole Impactor Based on ANSYS
Abstract In the present work, a down-to-the-hole electric hammer driven by linear motor is reported for drilling engineering. It differs from the common hydraulic or pneumatic hammers in that it can be applied to some special occasions without circulating medium due to its independence of the drilling fluid. The impact stress caused by the reciprocating motion between stator and rotor and the fatigue damage in key components of linear motor are analyzed by the ANSYS Workbench software and 3D model. Based on simulation results, the hammer’s structure is optimized by using special sliding bearing, increasing the wall thickness of key and multilayer buffer gasket. Fatigue life and coefficient issues of the new structure are dramatically improved. However buffer gasket reduces the impactor’s energy, different bumper structure effect on life improving and energy loss have also been elaborated.
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.