Papers by Keyword: Simulation Analysis

Abstract: Accurate characterization of low-resistance ohmic contacts on 4H-SiC is crucial for devicedevelopment, but is complicated by the limitations of the standard Transfer Length Method (TLM).TLM test structures are widely used for extracting the specific contact resistivity (ρC) between metaland semiconductor layers, as well as the sheet resistance of doped layers. The contact formation pro-cess itself, particularly the annealing step, modifies the SiC layer under the contact. This results in asheet resistance below the contact (RSK) that deviates from the sheet resistance of interest between thecontacts (RSH), which invalidates a key assumption of the standard TLM evaluation of a constant RSHthroughout the whole TLM test structure. This study uses 2D TCAD simulation of TLM test structuresto investigate the influence of the contact length L, while using an advanced evaluation method forextracting ρC with the help of a third contact. Consequently, it is necessary to measure the contactend resistance RCE, which is derived from the potential at the end of the TLM contact. The findingsprovide a deeper understanding of the TLM technique’s robustness and offer valuable guidelines foroptimizing TLM test structures to ensure accurate characterization of ohmic contacts on 4H-SiC.

Abstract: The work focuses on building a sophisticated legged-wheel model that will perform in different terrains for convenient locomotion. Although a variation of wheels is available for different vehicles, locomotion mechanisms, or robotics, there is still a lack of convenient transformable wheels for even and uneven environments. When focusing on wheelchairs, the main obstacle is seen in stairs. Hence, the focus of this work is to model and analyze a transformable wheel for a wheelchair. Several parameters will be examined to find the most optimal solutions. This work carried out 41 simulations to assess performance under various conditions, taking into account factors like leg length, number of legs, acting force, and rotor speed. It was found that, with the given environment, the following parameters were most optimal for the wheelchair to move on stairs and on even terrain. The wheels with a length of 19 cm showed the best results for climbing stairs. A further increase in length would introduce instability. The optimal rotation speed was found to be around 20-22 rpm. At higher speed, it led to excessive resistance and instability. It was also found that a person's weight acting on the wheelchair is significant, as lighter weight results in slipping and incapability of climbing stairs. In concluding the findings, it is obvious that each parameter plays a vital role in the overall performance of the wheelchair.

Abstract: In this paper, by analyzing the structure and material characteristics of skid landing gear, the skid landing gear model is established by using CATIA software. In the explicit dynamic analysis type of ANSYS software, the force comparison between the impact surface of soil material and the impact surface of rigid material is made, combined with the change of momentum and energy in the process of touching the ground. This explains the necessity of landing drones on soft landing surfaces such as soil. In addition, LS-DYNA was used to simulate the dynamics of landing gear, and the strength of landing gear was analyzed according to failure criterion.

Abstract: In₂O₃/ITO multilayer thin film thermocouple is a new type of semiconductor thin-film thermocouple, which has broad application prospects. The interface diffusion between the layers is the main cause of its thermal oxidation failure. In this paper, an interface diffusion model of multilayer films is established based on Fick's second law. A sample of In₂O₃/ITO thin-film thermocouple was prepared, then designed and conducted high temperature test. According to the test results, the diffusion of substances between the film layers was analyzed. Based on the established interface diffusion model, a simulation calculation is carried out. The influence of interface diffusion on the life of In₂O₃ and ITO sensitive layer was quantitatively analyzed.

Abstract: Aiming at the problems of large temperature differences and inconsistent baking speeds at different positions in the tobacco chamber of the tobacco baking room, this paper proposes a complex structure processing technology of fan vent. according to the structure and drying principle of the baking room, ANSYS fluent simulation software was used to analyze the processing parameters of the heat flow field inside the baking room. combining the characteristics of positive and negative air supply baking, the processing and manufacturing parameters of the baking room were optimized, and then the baking comparison test was performed. The results show that: the forward and reverse air-baking method and the complex structure reduces the temperature difference in the interior of the smoke chamber; the forward and reverse air-bake method reduces the baking time by 11 hours, and reduces the coal consumption and power consumption by 12.6%, 48.5%, the standard deviation of temperature monitoring points in the baking room decreased by 44%.

Abstract: In this paper, two kinds of spatial position and attitude controllers based on fractional order algorithm and algorithm are designed. Based on the basic assumptions, the model is established and the control of the spatial positioning of the manipulator is studied. The control effects of traditional controller and fractional order controller are analyzed and compared by numerical simulation method. At the same time, the effects of parameters and of fractional order controller and controller on system performance are simulated and analyzed. The results show that the fractional order controller has faster and better robustness than the traditional controller. The research of fractional order controller has become a new method to predict the space trajectory tracking and positioning of the manipulator and to ensure the positioning accuracy of the manipulator.

Abstract: A meso-structure model of three-dimensional spacer fabric composite (3D composite) was built by using the finite element software Workbench, and simulation analysis of in-plane compression on the 3D composite was studied according to the model. The results show that the upper and lower face-sheet is the main load-bearing section macroscopically, while the piles are the secondary load-bearing one when the 3D composite is subjected to in-plane compressive load. The fibers play a major role microscopically, while the resin plays a minor one. From part magnifying stress distribution, it can be found that the maximum stress occurs in the warp yarns, interlaced with weft yarns, when the 3D composite is subjected to in-plane compressive loads in warp direction, and fracture appearance is parallel. Meanwhile, the maximum stress occurs in the weft yarns, interlaced with binder warp yarns, when the 3D composite is subjected to in-plane compressive loads in weft direction, and fracture appearance is random. From strain distribution of each component, it can be seen that the failure mode is the interfacial de-bonding between the fibers and resin when the 3D composite is subjected to in-plane compressive loads.

Abstract: Wheel is an important part in the overall structure of bicycles. So performances of wheels have a great influence on the performances of bicycles. For example, if we improve the shock absorption of wheels, the bicycle will have better riding comfort. Traditional bicycle wheel absorbs shock from rough roads using the tire. In this paper, we propose a new design concept for the bicycle wheel with shock absorption ability. Firstly, we perform force analysis for the bicycle wheels. In order to verify our calculation, we conduct the finite element simulation analysis. The calculations and simulations have good consistency. Based on the calculations and simulations, we replace the steel spokes with some soft materials. Through impact test, we find that the bicycle with shock absorbing wheels has better riding comfort than traditional one. Meanwhile, the soft materials reduce the weight of wheels. So the overall performances of bicycle are improved significantly.

Abstract: Taking the trapezoidal link rear independent suspension which is designed for Crossover as the object of study, the multi-body dynamic analysis software ADAMS/CAR is used to establish the kinematics model and carry out the simulation analysis. And then, study the influence of the suspension system on the vehicle handling stability and make the evaluation under the conditions of wheel travel, applied load and body roll, which provides a basis for optimizing the suspension and improving the handling stability of the trapezoidal link rear independent suspension to the Crossover.

Abstract: It is essential that the back seat of a vehicle has to be designed safely and reliably and at the same time meet the ECE R17, as to reduce the back seat casualties in accidents caused by luggage impact. This paper studies a sample of back seat frame and establishes its precise CAD model. It adopts nonlinear finite element methodology to simulate the object under the ECE R17. The results reflect two problems. One is the force absorption and anti-deformation of the split seat frame is too weak; the other is the fixed connections linking the frame to the holder is not tight enough causing easy fall-off if being shocked. The test and simulation results suggest the following alterations, respectively to substitute the previous split seat frame for a one-piece seat frame as to improve the overall stiffness and anti-deformation, to adopt one-piece structure on the center support bracket and increases its thickness by 0.5mm, keep the remaining mounting bracket structure unchanged. The analyses of the improved program demonstrate its superior anti-deformation under the regulations.