Abstract: Directional excavation technology in the coal mine laneway is the important research direction of integrated excavation project. This paper studies the changes of cutting section shape and boundary values caused by the swing of boom-type roadheader's cutting arm to calculate the maximum values of compensable pose deviation when cutting, as the research basis for the accuracy analysis of boom-type roadheader's directional excavation. This paper gives the calculation method of cutting arm control, spatial modeling and analysis of cutting head position changes caused by cutting arm in thought of the three-dimensional analytic geometry, and also gives verification in the way of Matlab graphics simulation. At last, a control method to compensate section boundary by cutting arm is put forward.
Abstract: Reverse Engineering, also known as reverse engineering, new products has become an important way for design and development is one of the field of advanced manufacturing in recent years, the research focus. This paper discusses the surface information acquisition, surface reconstruction, CAD model creation and stamping blank reverse key technologies to solve the conventional time-consuming measurements, detection is difficult and costly problem; more complete establishment of a suitable complex stamping die reverse engineering methods and tools, dies for similar products in reverse reference.
Abstract: This paper presents a time-harmonic coupled field analysis method to calculate the eddy current, loss and temperature fields in the end region of a 15MW hydraulic generator. The magnetic-thermal coupled field under different operating modes are calculated when the clamping finger is made of carbon steel and stainless steel respectively. The distributions of eddy current loss and temperature in the clamping finger show that the highest temperature of the clamping finger is far below the limiting temperature of the insulation. The material of the clamping finger should be selected as carbon steel when considering the manufacturing cost.
Abstract: The aircraft parts contain the information of a great number of curves and surfaces, which makes it a big challenge for the aircraft components’ Assembly Sequence Planning (ASP) processes. The traditional interference matrix has limitation of expressing the assembly direction and can easily lead to the failure of ASP optimization. Hence, an improved interference matrix is provided in this paper to deal with the aircraft ASP problem based on the Genetic Algorithms (GA). With the mainly consideration of assembly time according to the assembly sequence evaluation criteria, the objective function is established and evaluated. This paper presents an application of the method in the aircraft cabin door assembly process supported by an 863 program. Meanwhile, the verification of the approach is shown in the practical example on MATLAB platform.
Abstract: Rigid-viscoplastic finite element method was used to analysis the cold extrusion of the external boss and ring gear. Some groups of numerical models were built with different design parameters of die, geometric parameters of gear, processing conditions, and the service loads were investigated. Form the investigation; we predicted the forming defects occurring in the practice. Based on Archard model the lives of dies were predicted. The conclusion above has more guidance to the production.
Abstract: The relationship of the friction coefficient and the MTC were discussed, and the MTC and its effects on surface roughness were a theoretical analysised and experimental verification by AFM (atomic force microscope). The results show that the theoretical MTC tends to be minimal value then before the adhering effect to reach remarkable. Appropriate adjustments cutting parameters, the cutting process can always micro-cutting phase to reach the steady-thin chip, and no plowing phenomenon. So the surface residues highly were reduced and higher surface quality was achieved.
Abstract: Coaxial powder feeding with carrier gas is the key part of laser direct metal deposition (DMD) rapid prototyping system. The convergence of powder flow would greatly affect forming efficiency, precision and performance. Numerical calculation model of flow field was built and simulated in this paper. The results of simulation and analysis had shown that powder flow field was very complex. The flow process could be divided into two parts, converging process and dispersing process. The main influencing factors of convergence included powder feeding rate, carrier gas flow rate, and the distance from nozzle to molten pool. There was a convergent focus where utilization ratio of powder was maximum. So the distance from nozzle to molten pool must be adjusted to equal to convergent focus (1.5cm) during DMD.
Abstract: The simulation of temperature field during laser direct metal deposition(DMD) were researched. The finite element model of single track cladding, multi-track overlapping and multi-layer deposition were established. The temperature field was simulated by ANSYS software basing on life-and-death element and cycle algorithm. Under different process parameters, the temperature and temperature gradient on the cross-section of sample were simulated during single- track scanning, multi-track overlapping and multi-layer deposition. Temperature cycle curves at different position were analyzed and were consistent with actually value. Both simulation and experiment showed that heat accumulation during continuous forming greatly affected the temperature of molten pool.
Abstract: This paper reports a finite element analysis of the compressive behaviour of circular inclined CFST stub columns. A set of test data were used to verify the FE modeling. Typical curves of vertical load versus longitudinal strain, stress distributions of concrete, interaction of concrete and steel tubes, as well as effects of important parameters that determine failure modes of the composite columns were investigated. The results clearly show that the FE modeling is available for predicting the capacities of the circular inclined specimens.