Multi-actuator Switch-mode Hydraulic System a Major Qualifying Project Report
Current hydraulic systems involving multiple actuators and a single hydraulic power supply generally have poor efficiency. Using throttling valves to control multiple actuators requires meeting the highest pressure requirement and the total flow of all of actuators. When there is a large difference in the pressure requirement of the actuators, fluid throttling results in significant energy losses. The purpose of this project is to implement switch-mode control in a multi-actuator circuit and demonstrate the improvement in efficiency over a traditional hydraulic system with throttling valve control. To accomplish this task a hydraulic crane arm powered by two actuators was designed and constructed. One actuator provides a pivoting motion utilizing low pressure and high flow, while the other provides a lifting motion utilizing high pressure and low flow. Using a simple feedback control loop, the crane arm lifts, rotates, and lower a load. After designing and testing the hydraulic crane, the team concluded that high-speed switch technology with multiple actuators is feasible. This new technology, once implemented on a larger scale in realistic applications, will reduce losses in hydraulic systems that depend on multiple actuators to function.
Machine Design: An Integrated Approach
1. Introduction to Design. 2. Materials and Process. 3. Load Determination. 4. Stress, Strain, and Deflection. 5. Static Failure Theories. 6. Fatigue Failure Theories. 7. Surface Failure. 8. Design Case Studies. 9. Shafts, Keys, and Couplings. 10. Bearings and Lubrication. 11. Spur Gears. 12. Helical, Bevel, and Worm Gears. 13. Spring Design. 14. Screws and Fasteners. 15. Clutches and Brakes. Appendix A. Cross-Sectional Properties. Appendix B. Mass Properties. Appendix C. Material Properties. Appendix D. Beam Tables. Appendix E. Stress Concentration Factors. Appendix F. Introduction to TKSOLVER. Appendix G. Introduction to MathCAD. Appendix H. Answers to Selected Problems. Appendix I. List of Software Included on CD-ROM.
Numerical Simulation of Thermal Sensitivity for Explosives
In order to compare the thermal sensitivity of several typical explosives, this article solved numerically one-dimensional transient heat conduction equation including thermal decomposition for explosives with finite difference method. The explicit difference equations under different boundary conditions were established, and the corresponding stability criterion was derived. The ignition times for typical explosives were calculated, which was used to evaluate thermal sensitivity of explosives.