Chang Jie Luo

Study on High Strength Metal Cellular Automatic Forming Technology and Equipment

The existing technology of stretching and forming metal honeycomb processing has obvious deficiencies. In order to develop metal honeycomb with high strength and better performance, this paper did extensive research on the technology of semi-regular hexagon corrugated structure forming and overlay process. Modern mechanical methodology was then employed to optimize high strength metal cellular automatic equipment and the best principle schema was selected. Each modules structure of the high strength aluminum honeycombs automatic overlay assembly equipment has been designed. Products were made based on the new design and went through a series of tests. The results demonstrated that this new method has greatly resolved the existing problems regarding the processing technology of aluminum honeycomb.

Axial Compression and Energy Absorption Characteristics of Reduction Tubes Using a Die under Impact Load

Reduction tube using a die is a kind of deformation tubes which are used on railway train as energy absorbers. In this paper, axial compression behavior and energy absorption characteristics of reduction tubes using a die under impact load are investigated. No-linear finite element software LS-DYNA is used to conduct the numerical study. Results for the expansion tube using a die (another kind of deformation tube) and the reduction tube using a die are compared. Assuming two different structures with the same material and sectional area, an analysis shows that the energy absorption of reduction tube is better than the expansion tube. Hence, the reduction tubes using a die are investigated using a series of numerical analysis. The relationship between displacement and load, average load are obtained. The influences of impact mass and impact velocity are discussed.

Design and Optimization of Honeycomb Corrugated Chaff Forming Roller

Abstract. By analyzing the material properties and forming characteristics of the 0.8mm length side hexagon honeycomb corrugated chaff , we studied forming roller’s design and optimization while making corrugated chaffs used forming method and focus on the influence of the chamfer of teeth top edge and number of teeth to forming quality at the corrugated chaff corner .We used finite element analysis software ANSYS / LS-DYNA to simulate the forming process of corrugated chaff , studied the stress contour and stress-time curve of typical element, found the optimal chamfer of teeth top edge and number of teeth, then we used the designed forming roller to verify the effect of chaff forming . By comparison experimental and simulation results,we found good agreement between the two, when the chamfer of teeth top edge dj = 0.08mm, number of teeth z = 40, the chaff has the best forming quality .

Effect of Geometry on Energy Absorption of Reduction Tubes Using a Die - A Numerical Study

The present paper deals with the numerical study of energy absorption of reduction tubes using a die subject to axial impact load. Non-linear finite element software LS-DYNA is employed to analyze the deformation pattern and energy absorption characteristics. The tubes, with the bottom ends constrained axially, deformed in necking modes by the axially moving dies. The geometries of the tubes and the dies were varied to find out the influence of the geometry parameters. The strain rate effect of the material is considered and the Cowper-Symonds equation is applied in the plastic dynamic analysis.

Optimization Study on the Tooth Profile of Gear Shaping Roller of Honeycomb Semi-Cell Structures

In order to solve the problem of low accuracy of honeycomb semi-cell structures which are rolled by traditional trapezoidal tooth profile gear shaping rollers, conjugate trapezoidal tooth profile gear shaping rollers have been put forward to improve the quality of honeycomb semi-cell structures, basing on the theoretical analysis. Using ANSYS/LS-DYNA, a finite element model of rolling aluminum foils by two kinds of tooth profile shaping rollers was set up. Then results of numerical simulation indicate that the honeycomb semi-cell structures rolled by the conjugate trapezoidal gear shaping rollers are closer to the ideal size than those rolled by the traditional trapezoidal gear shaping rollers.

Study on Preparation Method and Energy-Absorbing Characteristics of Carbon Fiber Composite Energy Absorber

By analyzing advantages and disadvantages of the existing energy absorbers, carbon fiber composite and regular hexagon honeycomb structure were chosen as material and topological structure respectively to make a big-bearing, lightweight energy absorber. Preparation method of carbon fiber composite honeycomb energy absorber was studied, which was applied to manufacture some specimens,and it is feasible because of the specimens good consistency and regularity. Quasi-static compression tests of the specimens were carried out, and then the related parameters of energy-absorbing characteristics were calculated. The results show that the carbon fiber composite honeycomb energy absorber has excellent energy-absorbing characteristics.

Study on a New Forming Method of the Honeycomb Semi-Cell Structures

A new forming method of honeycomb semi-cell structures was proposed by analyzing the defects of finished products processed by traditional roll forming method. Using ANSYS/LS-DYNA, a numerical analysis of its forming process was set up. A new forming equipment has been developed to conduct experiments. The results of experimental and numerical analysis show that the new forming method of the honeycomb semi-cell structures is feasible and superior.

Thermodynamic Performance of Ammonia Water Power Cycle (AWPC)

This paper introduces the ammonia water power cycle and presents the cycle performance criteria such as net power output, net power energy per ton of geothermal water, heat efficiency and heat exchanger area of per net power. The cycle influencing factors such as ammonia concentration, solution circulation ratio and hot water temperature are analyzed. Results show that there is an optimum range of ammonia concentration and solution circulation ratio. The power system exploits a new way for utilizing the mid-low temperature heat resource efficiently.

Numerical and Experimental Investigations on the Expansion Tube Energy Absorber

Expansion tube energy absorber is of interest in bumper device on the spacecraft, for example the seat-bumper and its crushing characteristics have shown an excellent performance. This paper contributes to the analysis and investigation of the crushing characteristics of the expansion tube energy absorber, by simulating the response of the 2Al2T4 expansion tube subjected to quasi-static axial compressive loading, using the LS-DYNA finite element code. Corresponding tests were conducted to serve as comparison purpose. Satisfactory level of agreement between simulation and testing results was obtained regarding the main characteristics of the tested expansion tubes such as peak compressive load, energy absorption and the overall compressive response. Formula of the crushing force deduced using plastic mechanic theory was checked. Impact model was also constructed and dynamic simulations were performed to investigate the axial impact response of the expansion tube energy absorber. The simulation results of quasi-static and dynamic compression response of the expansion tube are very similar.

Energy Wave Transmission and Control Analysis in Force Reflection Teleoperation Based on Interconnected Power Line

Force-Reflected Telepresence Teleoperation system has been widely used. Generally, force and torque sensors are installed on the robot to realize haptic perception. Control commands and force-reflected information from the robot are transmitted by communication link, such as internet. However, this structure not only brings difficulties of installation and commissioning, but also reduces the system flexibility and makes control more difficult. And it is prone to interfered in microenvironment. This paper presents a new type of energy transfer method to achieve it by power line instead of internet between the Master-slave Manipulators. This method achieves the consistency of force-reflected without using sensors to measure the conditions. In practical application, it requires to design an energy managed controller to insure the stability and obtain precision in synchronization between the master part and slave part. This paper gives the theory, the system structure and control method of force telepresence teleoperation based on power line.