Applied Mechanics and Materials Vols. 80-81

Abstract: With the development of modern industrial society, the need of measuring the pressure parameters at the ultra-low temperature is proposed. However, there is no developed products of ultra-low pressure sensors at home and abroad, and reports related to ultra-low pressure sensors such as the structural design of and methods of test and calibration are also few. This paper mainly describes a method for test and calibration of the pressure sensor at the ultra-low temperature. Based on the requirements obtained under the ultra-low temperature condition, a calibration device for the pressure sensor at the ultra-low temperature is designed, and the specific calibration instructions of some parameters are given.

Abstract: Bead-on-plate welds was made by underwater wet welding with flux-cored wire in a tailor-made pentrough. The effect of welding parameters such as welding speeds, welding currents and welding voltages on welds surface appearances and microstructure were studied. Orthogonal experiment method was used to optimize combination of different welding parameters. The results showed that the hardness (HV) of welds fusion zone ranged between 515 and 670 while the hardness (HV) of base metal was only 350. The fusion zone of the welds was mainly composed of columnar grain structure.

Abstract: This paper give a diesel particulate filter (DPF) regeneration equipment based on LPG (Liquefied Petroleum Gas), which the filter bodies of both the DPF were made of winded metal mesh, to fit for the high sulfur diesel. Development of performance external LPG heating regenerative devices can be completed within 20 minutes DPF regeneration. This regenerative device control system using MCU by reading the temperature controller and pressure sensor data, output analog quantity to control the frequency converters, which control blower speed to achieve the control of air flow into the burner, to achieve temperature control. To ensure system security, the use of burner control to achieve the various components of the control scheduling. It is cheap, good durability, a high degree of confidence. Because they do not use the catalyst can be regenerated, so it can be used in high-sulfur diesel.

Abstract: The seal deformation of automotive door is caused by the door compression forces, including non-linear elastic force and non-linear damping force. The working principles of them are analyzed and a new simplified analysis model is built. Based on the Bernoulli equation and the law of conservation of mass, the mathematical models are established to calculate energy consumption of the seal system. According to the analysis results, the energy consumption of non-linear elastic force and non-linear damping force are respectively 84% and 16% of the total energy consumption of the seal system. At last, the calculation data is compared with the test data and the error is less than 5%, so the calculation method proposed in this paper is observed to be accurate.

Abstract: Firstly, the index system influencing cleaning quality was established based on AHP theory and the weight were calculated. According to the weight value, the key factors which affected cleaning process were determined. Secondly, the model calculating the weak degree of index factors was established by introducing a basic concept (eligible degree) from extendable optimal degree. According to the weak degrees, using the method for determining the number of principal components in principal components analysis method, the weak factors were determined in key factors. Finally, taking the cleaning process of cooling system of the car diesel engine in some repair factory for an example was analyzed, the result showed that the method to determine weaknesses was effective.

Abstract: The acquisition of steady-state data is the premise for optimizing the boiler combustion parameters. Assuming the measuring parameters obey the Gaussion distribution, this paper uses the large-probability distribution interval to approximate the variation range of random variable, constructs appropriate working condition matrix whose column quadratic sum approximately obeys the Chi-square distribution, and then obtains the Chi-square distribution based steady-state data judgment criterion. The judgment threshold of this criterion could be self-adaptive. This judgment criterion has been validated by an experiment.

Abstract: The main and control circuit of co₂ welding power, which is mode of full-bridge and IGBT inverter, is designed based on DSP (Digital Signal Processor). The designing include sub-modules based on DSP such as the sampling signal circuit, the control circuit for external characteristics, the PWM (Pulse-Width -Modulation) control circuit of welding inverter, the IGBT drive circuit and etc. This designing can strengthen the reliability of feedback regulation property on co₂ inverter welding power can enhance the stability of the parameters from the power system. The experimental result shows that the inverter welding power has good feedback regulation and stability properties during the co₂ welding process.

Abstract: Electrospun nanofiber is widely used in cartilage tissue engineering to fabricate the replacement for the lost or damaged tissues and organs.The recent research has showed that the fiber diameter plays an important role in the scaffold degradation rate and growth rate of the planting cells,therefore whether the fiber diameter could be controllable or not is related to the further development of cartilage repairment engineering. For that sake,this paper suggested a control method basing on the finite element numerical simulation,which could be seen as an experiment plotform,furthermore the controller is trained according to the data collected from the model,and the control effect is examed and fixed as well.This method broke through the traditional type to exercise controllor that basing on identifide transformation model,it promotes the accuracy of the controllor to a large degree. After all,it is also an effective job to realize the flexible production and manufacturing of the equipments.

Abstract: The work condition of the air cushion suspension technology was simulated numerically based on CFD technology. In order to comparing with different work conditions, at the beginning of the subject, three different pressure inputs have been given. Based on the velocity magnitude cloud and streamlines, the vortices generated by the input flow on the wall of the air cushion balloon had also been investigated and some conclusions were drawn.

Abstract: Design of self-energizing shock absorber of suspension of SVU, a multi degree of freedom mechanism, is a challenge. In order to decay vibration and recycle energy, self-energizing shock absorber was researched. This paper primarily focuses on kinematics and dynamic analysis in multi-body system (MBS) and validation of system. A simulation model for self-energizing shock absorber was built using the software MATLAB, and the establishment of this model was based on the analysis of internal configuration and characteristics of valves. Vehicle simulation model was built using MBS. The assembly between vehicle simulation model and the shock absorber was realized through co-simulation between MBS and MATLAB. The optimal design of suspension is investigated, in order to improve vertical ride and road-friendliness of vehicles, while maintaining enhanced roll stability. A nonlinear vehicle model is developed to study vertical as well as roll dynamics of vehicles. The simulation results shows that suspension with self-energizing shock absorber can partly energy-regenerative which can be used to adjust ride height due to load change of automobile. Self-energizing shock absorber is also improving the ride performance of vehicle.