1992 Vol.5(3)
Display Mode： |
1992, 6(3).
Abstract:
The objective function of Cutting Process Optimization (CPO) problem is proved of being without extreme value itself, and on the basis of it a Bouundary-Value-Comparison (BVC) method is proposed for the problem solving. Several relevant problems of the application program of the method on a computer are discussed. Finally an example of the use of the method if given and the results show that the computational time may be reduced more that 10 times compared with the commonly used mathematical programming method.
The objective function of Cutting Process Optimization (CPO) problem is proved of being without extreme value itself, and on the basis of it a Bouundary-Value-Comparison (BVC) method is proposed for the problem solving. Several relevant problems of the application program of the method on a computer are discussed. Finally an example of the use of the method if given and the results show that the computational time may be reduced more that 10 times compared with the commonly used mathematical programming method.
1992, 6(3).
Abstract:
In this paper, a solution was presented on the basis of a great number of calculating results by means of three dimensional finite element method, which can be used to calculate the Stress Concentration Factor for large openings in cylindrical thin wall pressure vessels. The solution was compared with Eringen's. Decock's and Lind's solutions. An experiment has been made to make sure whether the models of the finite element are appropriate and the computing program is accrate. The experiment and analysis show that this solution is more reasonble, accurate and valuable for the stress analysis and engineering design of the cylindrical presssure vessels with openings.
In this paper, a solution was presented on the basis of a great number of calculating results by means of three dimensional finite element method, which can be used to calculate the Stress Concentration Factor for large openings in cylindrical thin wall pressure vessels. The solution was compared with Eringen's. Decock's and Lind's solutions. An experiment has been made to make sure whether the models of the finite element are appropriate and the computing program is accrate. The experiment and analysis show that this solution is more reasonble, accurate and valuable for the stress analysis and engineering design of the cylindrical presssure vessels with openings.
1992, 6(3).
Abstract:
Based on the space meshing theory and by the aid of CAD technique, this paper proposes a design method for controlling the transmission backlash and optimizing the meshing parameters of a harmonic drive. The corresponding software presents the functions of designing configurational parameters, displaying and graphing automatically. It offers a feasible and simple way to extend the application of the new type of transmission technique with harmonic drive in our country.
Based on the space meshing theory and by the aid of CAD technique, this paper proposes a design method for controlling the transmission backlash and optimizing the meshing parameters of a harmonic drive. The corresponding software presents the functions of designing configurational parameters, displaying and graphing automatically. It offers a feasible and simple way to extend the application of the new type of transmission technique with harmonic drive in our country.
1992, 6(3).
Abstract:
In this paper an innovative method for machining sculptured surfaces is presented. By using a disc cutter with a concave end instead of traditional ball-ended or drum-shaped tools, and by adjusting the cutter axis to tile relatively to the workpiece being machined under some specific rules, the envelope formed by the trace of the tool-nose in each pass and the required theoretical surface have the same derivatives up to the third order in the plane normoal to the feeding direction. As a result, the number of machining strokes needed can be greatly reduced while the same accuracy is guaranteed. Some essential algorithms for the new method are proposed, together with an example.
In this paper an innovative method for machining sculptured surfaces is presented. By using a disc cutter with a concave end instead of traditional ball-ended or drum-shaped tools, and by adjusting the cutter axis to tile relatively to the workpiece being machined under some specific rules, the envelope formed by the trace of the tool-nose in each pass and the required theoretical surface have the same derivatives up to the third order in the plane normoal to the feeding direction. As a result, the number of machining strokes needed can be greatly reduced while the same accuracy is guaranteed. Some essential algorithms for the new method are proposed, together with an example.
1992, 6(3).
Abstract:
Plasma-sprayed ZrO2 coating subjected to Hot Isostatic Pressing(HIP) is more compact and more homogeneous, having better performance and greater adhesion strength with the steel substrate. The pores can be easily chosed up and less cracks developed if the ZrO2 coating is doped with appropriate amount of SiO2. After HIP treatment, the bonding between ceramic layer and adhesion layer is of mixed mechanical and metallurgical nature. The conding between the adhesion layer and the steel substrate is of pure metallurgical nature. Fe-Al-C intermetallics containing Ni were found at the interface which consisted of two sub-layers: the Ni containing Fe-Al-C intermetallics and the decarburized (ferrite) sub-layers.
Plasma-sprayed ZrO2 coating subjected to Hot Isostatic Pressing(HIP) is more compact and more homogeneous, having better performance and greater adhesion strength with the steel substrate. The pores can be easily chosed up and less cracks developed if the ZrO2 coating is doped with appropriate amount of SiO2. After HIP treatment, the bonding between ceramic layer and adhesion layer is of mixed mechanical and metallurgical nature. The conding between the adhesion layer and the steel substrate is of pure metallurgical nature. Fe-Al-C intermetallics containing Ni were found at the interface which consisted of two sub-layers: the Ni containing Fe-Al-C intermetallics and the decarburized (ferrite) sub-layers.
1992, 6(3).
Abstract:
In this paper, the engagement of the rack and pinion steering gear with variable ratio is emphatically discussed by means of conjugate theory. The method and procedure are established to calculate the teeth flanks of the rack. Meanwhile, a significant conclusion is drawn: the rack and pinion remain in linear mesh regardless of the installation angle and the ratio, and the teeth flanks of the rack are developable. Furthermore, the machining mechanism is studied, with some valuable results obtained.
In this paper, the engagement of the rack and pinion steering gear with variable ratio is emphatically discussed by means of conjugate theory. The method and procedure are established to calculate the teeth flanks of the rack. Meanwhile, a significant conclusion is drawn: the rack and pinion remain in linear mesh regardless of the installation angle and the ratio, and the teeth flanks of the rack are developable. Furthermore, the machining mechanism is studied, with some valuable results obtained.
1992, 6(3).
Abstract:
Due to the thermal-rate treament, the primary silicon grains in hypereutectic Al-Si alloy are remarkably refined, so that the tensile strength of the alloy increases by about 10%; meanwhile, as the silicon phases in the eutectic Al-Si alloy are modified the elongation of the alloy increases by over 40%. Temperature inflexions on the differential thermal curves are detected during the cooling of the molten eutectic Al-Si alloy from high temperatures.
Due to the thermal-rate treament, the primary silicon grains in hypereutectic Al-Si alloy are remarkably refined, so that the tensile strength of the alloy increases by about 10%; meanwhile, as the silicon phases in the eutectic Al-Si alloy are modified the elongation of the alloy increases by over 40%. Temperature inflexions on the differential thermal curves are detected during the cooling of the molten eutectic Al-Si alloy from high temperatures.
1992, 6(3).
Abstract:
The final sensitivity of a Force-Measuring Bearing depends totally on its strain gauge distribution pattern and bridge connecting manner when the optimum depth of strain gauge distributing groove has been determined. In this paper, photoelastic experimental method was applied to analyze visually the stress distribution pattern of a FMB's photoelastic model in detail. Stress distribution curves under different loading conditions were aquired. The experimental results point out some defects in conventional strain gauge distribution pattern and provide reliable reference bases for the determination of the optimum strain gauge distribution patterns under different application conditions.
The final sensitivity of a Force-Measuring Bearing depends totally on its strain gauge distribution pattern and bridge connecting manner when the optimum depth of strain gauge distributing groove has been determined. In this paper, photoelastic experimental method was applied to analyze visually the stress distribution pattern of a FMB's photoelastic model in detail. Stress distribution curves under different loading conditions were aquired. The experimental results point out some defects in conventional strain gauge distribution pattern and provide reliable reference bases for the determination of the optimum strain gauge distribution patterns under different application conditions.
1992, 6(3).
Abstract:
In this paper, a study of torsional undamped free vibration problem on the basis of experiments is presented. The two degree of freedom vibration model of harmonic gear drive using for general purpose is established and mathematical solution of its characteristic value is presented. Based on calculation of the XBD80-100-120-Ⅰ harmonic gear reducer, the sensitive parameters and sensitive interval effecting on first order natural prequency can be obtained. The experimental result proves that harmonic gear drive always runs in the performance of interference of multifrequency exciting force. By means of 3-dimension frequency spectrum figure of the tangential acceleration of putput shaft in relation to different rotating frequency of motor, the first order natural frequency of the system can be determined.
In this paper, a study of torsional undamped free vibration problem on the basis of experiments is presented. The two degree of freedom vibration model of harmonic gear drive using for general purpose is established and mathematical solution of its characteristic value is presented. Based on calculation of the XBD80-100-120-Ⅰ harmonic gear reducer, the sensitive parameters and sensitive interval effecting on first order natural prequency can be obtained. The experimental result proves that harmonic gear drive always runs in the performance of interference of multifrequency exciting force. By means of 3-dimension frequency spectrum figure of the tangential acceleration of putput shaft in relation to different rotating frequency of motor, the first order natural frequency of the system can be determined.
1992, 6(3).
Abstract:
In this paper a lose loop control system of welding arc and weld pool quality developed at Tsinghua University is introduced. Is consists of three parts, namely, adaptive control of pulse MIG/MAG welding, penetration control of the weld bead and automatic seam tracking. Principle of operation, special features and experimental result are described.
In this paper a lose loop control system of welding arc and weld pool quality developed at Tsinghua University is introduced. Is consists of three parts, namely, adaptive control of pulse MIG/MAG welding, penetration control of the weld bead and automatic seam tracking. Principle of operation, special features and experimental result are described.
E-mail Alerts
