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Combined numerical simulations and experimentally measured data, the relationship between the initial temperature of the workpiece was described, the stamping speed, and the required forming force. Air cooling was included to determine the temperature of the part within the mold, and the required stamping force was optimized by studying the impact of the cooling time on the temperature of the part. The optimized model was verified and validated by comparing simulated data for an anti-collision beam with the experimental results of the hot-forming process. The results showed that the model provides a useful description of the hot-forming process; however, an empirical factor of 0.95 was required to achieve agreement between the simulated and experimentally measured data.

High-cycle fatigue damage analysis and life prediction is a most crucial problem in the research field of solid mechanics. Based on the thermodynamic potentials in the framework of thermodynamics a numerical method for high-cycle fatigue damage was studied and provided by using a two-scale damage model. Furthermore, according to the “jump-in-cycles” procedure the numerical simulation of high-cycle fatigue damage was implemented in a user subroutine of ABAQUS software. Finally, a numerical simulation instance of high-cycle fatigue damage was provided and compared with a set of test data, which indicates that the numerical simulation method presented is reasonable and applicable.

In order to improve the rate of finished products, failure analysis of 35CrMoA high speed train shaft was carried out by means of chemical analysis, gas element analysis, macrostructure check, fracture pattern analysis, metallographical analysis, hardness testing and other analytical methods. The results show that the big forged cracks are caused by serious non-metallic inclusion and improper hot working processes. And the brittle fracture of the shaft is mainly caused by big forged cracks and great residual stress. Meanwhile, it has suggested that the shaft should be detected by supersonic wave along axial and radial direction after forging and heat process.

As technology advanced, moving target tracking system is used more and more widely. But the traditional tracking systems are much restricted of imaging and tracking devices. This paper developed system based moving target tracking which could have a broader scope of application. The system does not have to be limited to tracking devices, but the application of the model matching technique and IMAQ Vision modules of Labview environment to form the framework of the virtual instrument system, and finally through the experiment to verify the practicality of the system.

OFDM is a special multi-carrier modulation, its basic idea is to make high-speed transmission of data flow through the serial-parallel conversion and make it to be the low-speed transmission of data flow in a number of narrow-band orthogonal sub-channels. However, a major drawback of OFDM signals is their high Peak-to-Average Power Ratio (PAPR), which makes the inter modulation distortion occur due to the nonlinearity of the high power amplifier. The distortion severely deteriorates the performance of the OFDM systems. According the problems mentioned above, this dissertation focuses on the reducing the PAPR algorithms design for OFDM systems, such as SLM and PTS. In summary, this paper has completed the OFDM system simulation with Matlab and analyses the result.

The detailed analysis of the structure and paramerers of the connecting rod is put forward by using the improving D-H method to establish the link coordinate system and the kinematics equation, based on the special filer shell arc welding robot with six degrees of freedom designed. Therefor, the correctness of the kinematics equation is verified though the simulation of Matlab function with the robotics toolbox. The anasysis simulation results show that the rationality of the robot structure that based on the kinematics analysis, is feasible.

The distribution of temperature on the rubbing surface is an important factor influencing the lifetime of a brake disc. With a copper-base sintered brake pad and a forge steel disc, up-to-brake experiments have been conducted on a full-scale test bench at a highest speed of 200 Km/h and a maximum braking force of 22.5 KN. The temperature distributions on brake disc surface have been acquired by an infrared thermal camera, and the contact pressure on the contact surface of the friction pair has been calculated by the finite element software ABAQUS. The results show that the area and thermal gradient of the hot bands increase with the increase of braking speed and braking force. The hot bands occur in priority at the radial location of r=200 mm and r=300 mm, and move radially in the braking process. The finite element modelling calculation indicates that the distribution of the contact pressure on the disc surface in radial direction is in a "U"-shape. The maximum contact pressure occur at the radial locations of r=200 mm and r=300 mm, and the minimum contact pressure occur in the vicinity of the mean radius of the disc. The conformity of contact pressure distributions with the practical temperature evolutions indicates that the non-uniform distribution of the contact pressure is the factor resulting in the appearance of hot bands on the disc surface.

In this paper, the dynamic performance of the single rod magnetorheological damper (MRD) without accumulator in different working status is researched, which is a new type of MRD developed by us to apply in the environment of explosion and shock. It is concluded that there is no offset force in the new MRD. The maximum damping force and energy absorption capability increase non-linearly with the excitation current and piston’s velocity. The mechanical model of this type MRD is proposed. By comparison of the results of tests with simulation, it is proved that the mechanical model proposed in this paper can simulate the dynamic performance of the new MRD accurately.

Base on reduction experimental data, considering the reduction process factors like carbon content, reductive removal of ZnO, changing size of pellet, and partial pressure of reducing gas, also coupled heat transfer, mass transfer and chemical reactions, a direct reduction mathematical model on carbon-bearing pellet containing zinc has been established. The reliability of the model was testified by programming and experiments. Experiments showed that, under the reduction conditions that carbon and oxygen mole ratio at 1.0 and reduction temperature 1603K, metallization rate 87% and dezincification rate 99% were observed after 15 minutes of heating.

Healing processing of the samples of a 45 steel was carried out. The healing area of inner cracks in the sample made by method “Drilling – Compressing” was observed and analyzed. SEM and FESEM analysis displayed that the microstructure in healing area is should be was mainly ferrite, and ferrite grain growth across the interface of inner crack, and there exists should be exist many polyangular grains of several hundreds nanometer in ferrite of healing area. Vickers-hardness test showed that the hardness of ferrite in healing area is should be was higher than that in matrix, which may result from the strengthening of polyangular grains.