Based on product simulation software, FEA method is used to identify the structural modal of instrumented indentation equipment frame which is the main supporting part of the High-precision instrumented indentation tester developed and realized by our group. From dynamic finite element computations, the multistage natural frequencies of tester frame are derived. The first 6 ranks vibration frequencies are all less than 10Hz, therefore, the loading and unloading process should be kept in quasi static state so as to prevent system resonance.

Now we make theoretical analysis to cost reduction of corrugated pipe in present R410A refrigerant sys-tem and put forward a size of material feeding with light pipe to realize cost reduction according to R410A refrigerant physical properties as well as pressure formula to biggest test of corrugated pipe.

Based on the finite element analysis method to simulate the O-P hardness. Taking S45C steel as an example, comparative analysis of O-P hardness of finite element simulation and O-P hardness of instrument indentation hardness experiment, results show that difference of S45C steel’s O-P hardness between the finite element simulation and real experiment is-2.62% Accordingly seen, O-P hardness can be obtained by finite element numerical simulation method, it’s a possible way to study relations between O-P hardness and Vickers hardness based on finite element numerical simulation techniques.

Based on the finite element analysis method, the relationship between two systems of crack (radial crack and lateral crack) and pop-in phenomenon were compared during the instrumented indentation process in ceramic materials. In order to give a reasonable explanation for mechanism analysis of pop-in phenomenon in the process of ceramic materials instrumented indentation, this paper proposed the viewpoint that pop-in phenomenon is caused by the lateral crack in the process of ceramic materials instrumented indentation. This work provided a theoretical basis for the study of instrumented indentation methodologies based on the pop-in phenomenon to determining mechanical properties of ceramic materials.

A novel high accuracy instrumented indentation tester for measuring material mechanical properties has been developed; the tester adopts three probe type capacitance displacement sensors combined with a depth measuring desk that are used as the reference of displacement measurement, and works in indentation depth measurement mode. As a significant feature, the tester eliminates the depth measurement errors caused by sample surface slight incline, frame deformation and sample fixation deformation, and therefore ensures the measurement accuracy of the fundamental data, i.e. the indentation depth of a diamond tip penetrating into the tested sample. Additionally, the driving part and load sensor of the tester are designed with a separate scheme, which avoids the thermal drift of load measuring data and ensures the measurement accuracy. As for the measurement principle, the tester adopts our self-developed new principles and methods for measuring material mechanical properties, which solves the problem of low accuracy of conventional test methods widely used in other commercial instrumented indentation testers in the world. Using the newly developed tester, the Young's moduli of 6061 aluminum alloy and S45C carbon steel were determined, which verifies the accuracy of the developed tester.

Based on dimensional analysis, finite element numerical calculation is undertaken on elastic–plastic solids to investigate the relationship between instrumented indentation nominal hardness Hn and reduced elastic modulus Er for three different apex angle indenters. The half-included angles of axisymetric conical indenter models are 62.9°, 70.3°and 85.566° which are corresponding to the real indenters of cube corner indenter with 60° face angle, Berkovich indenter with 65.27° face angle and cube corner indenter with 85° face angle, respectively. The relationship between a nominal hardness/reduced elastic modulus (Hn/Er) and elastic work/total indentation work (We/Wt) is established with a sixth-order polynomial form for each apex angle indenter. For rigid indenter of instrumented indentation model, reduced elastic modulus Er=1/[(1+v2)/E], where E and v are elastic modulus and Poisson’s ratio of the indented material. Therefore, Hn/Er–We/Wt relationship can be used to give estimates of E. Accuracy estimation for the each relationship of each half-included angle indenter shows that the large half-included angle of 85.566° gives better Er measurement error of +11.56% for a low yield strength material(e.g., materials for which σy=100MPa, n=0 and E=200GPa), while for the smaller half-included angle of 62.9° or 70.3° indenter, the measurement error is > ±12.74%. The research in this paper confirms that Hn/Er–We/Wt relationship of large apex angle indenter such as 85.566° half-included angle is recommended to be used for estimating the elastic modulus E of indented material.

Finite element analysis is undertaken to identify the extent of loading deformation of instrumented indentation equipment frame which is a main part in High-precision instrumented indentation tester developed and realized by our group. The working load enacted in the model is varied from 10N to 100N, and the increment load is 10N. By plotting and fitting data of inclination angle and working load, the relationship between frame inclination angle and working load is established. The function of this relationship is θ=0.000024*F. When the working load is up to the upper bound 100N, the inclination angle of frame reaches the maximum value 0.00241°.Load analysis of push rod shows that the percent error between measured load values and real indentation load values caused by maximum inclination angle is in 10-8order. The conclusion is thus derived that frame inclination has nearly no effects on load measurement precision. The research in this paper confirms that the design of frame belonging to High-precision instrumented indentation tester is appropriate.

Fracture toughness of structural ceramic materials can be obtained with one instrumented macro-indentation tester with a Vickers indenter, which is superior to the traditional method which first uses a nanoindentation tester or other instruments to get elastic modulus and then use a large load hardness tester to make crack on the sample surface. Fracture toughness of two ceramic materials: silicon nitride and zirconium oxide is tested on the instrumented macro-indentation tester. The results are 5.93 ~7.05MPam1/2and 7.68~8.57 MPam1/2.

Based on the instrumented indentation technique, an indentation tester with nanometer accuracy, which integrate the functions of driving, measuring, controlling and data-analyzing together, is presented in this paper. The test's intermediate error is decreased by loading with voice coil actuator without transmission mechanism And the signal is acquired from high-precision capacitive displacement sensor and strain gauge load cell. An closed loop control system based on PID algorithm is developed and control software is programmed. By analyzing the displacement influence factors, calibrating the instrument compliance and confirming the initial contact point, the accuracy of the testing result is guaranteed sufficiently.

The matters needing attention in the procedure of painting of stealth coating were expounded,the processing key was pointed out which was the cleanliness of base and thickness of the stealth coating.And the attentions in the proceure of painting,such as protection,thickness test and so on were also stated by practice and resut analysis.These results had good directive function to guarantee the painting quality of stealth coating.

According to the vector tube bending principle of the CNC pipe bender,use Pro/ENGINEER pipe feature for 3D modeling of air conditioner pipeline and 2D projection conversion,In combination with the CNC pipe bender program features,propose a reasonable way of bend dimensioning in order to facilitate Programming for the production process and parts inspection,reduce the number of test bends,to achieve productivity gains and production costs of the air-conditioner pipe fittings.

针对两种仪器化压入仪和两种代表性压入测试方法:Oliver-Pharr方法和Ma方法,通过有限元数值模拟分析了仪器柔度标定误差对2种仪器和两种方法测试精度的影响。结果表明仪器柔度的标定精度直接影响压入测试结果的准确度,仪器柔度越小,测试精度越高;就测试方法而言,Ma方法具有比Oliver-Pharr方法更高的精度和更低的仪器柔度敏感性;对同一材料,压入深度越大,由仪器柔度标定误差引入的压入测试结果误差越大;当材料较硬且压入深度较大时仪器柔度的标定尤为重要,小量的标定误差导致测试结果严重偏离真值,甚至为负值。

Most of passengers have motion sickness.The optimum drug for motion sickness patients is selected according to the analysis and comparison of various motion sickness drugs.Based on AT89C2051,the paper proposes the automobile anti-motion sickness device,which is equipped with anti-motion sickness drugs and real-time control system.The real-time control system is simulated by Proteus.The simulation results verify the efficiency and feasibility of the design.

A new wavelet transform algorithm based on the lifting scheme,which can remove noise signal in real time,is proposed.This algorithm is fast and can remove noise signal instead of the full data acquisition compared with the traditional wavelet transform algorithm,so this algorithm can be applied to the real time signal process.For explaining the working process,the flow chart of this algorithm is present too.By the experiments with the simulation signal and real time signal,it is found that this algorithm is effective and easy for application.

针对凸轮淬火后磨外圆时容易出现裂纹的现象,分析了其形成的原因,从工艺措施、砂轮的选择和修整等方面提出了改进方法,在实际生产中取得了很好的效果。

To reduce the noise of the punch press during the punching process, the polyurethane elastomer is used as the damping material. The experiments of reducing noise were made by means of adding the polyurethane elastomer at different positions on the 100 kN and 1 000 kN punch presses. The better effect of reducing noise was obtained. After researching and analyzing a large number of test data, the ″equivalent damping hypothesis″ is put forward. The hypothesis makes the experiment of reducing noise simpler and also more economical. It is estimated that there is a vast application in the research area of vibration control and noise reduction.

The techniques of making internal ceramic coating by static self-propagating high-temperature synthesis(SHS) method on the thin wall pipe,straight pipe,elbow pipe,tee pipe and double layer pipe were developed.A technology of static-centrifugal SHS was proposed.The possibility of using the ceramic coating as thermal insulation layer in the cylinder or exhaust channels or vent-pipe on engine has been researched.A new semi-solid working mould was developed using SHS coating technique.Details of the coating tests including coating process optimization,hot shock test,the flaw detecting by X-ray and the application experiments on liquid forging of steel and aluminum alloy were carried out.The results show that the ceramic coating on semi-solid forging mould can improve the service life of the mould remarkably.

由于模具等一系列问题,黑色金属半固态加工技术迟迟没能大规模进入工业实用化阶段.采用静态自蔓延法进行了制备半固态金属加工用陶瓷涂层模具研究.内容包括:熔涂前的表面预处理、熔涂后涂层磨削加工、熔涂工装研制、熔涂工艺、热震性测试和铝合金及高温钢质液态模锻应用试验.获得的制件质量良好、陶瓷涂层无损坏,表明涂层模具具有优异的工艺适应性,静态自蔓延技术可以用于半固态金属加工模具表面强化处理.

In this paper, a high speed hot extrusion process of NiTi shape memory alloy (SMA) tubes has been studied. The influences of temperature, heating means and lubricating method for forming state were presented. The distribution of the temperature and the influence of the extrusion speed on the temperature in the extrusion process have been analyzed by numerical simulation method. The results of the simulation agree well with the experimental. The hot extrusion process of NiTi SMA tube has been determined, which lays a foundation for the research on the process of a mass production of NiTi SMA tubes by the plastic forming method.

A model of composite materials consisting of a continuous matrix with multiple elliptical rigid inclusions was considered. The problem of interfacial stress maxima varying with shape of inclusions was solved accurately. Using the conformal mapping technique integrated with the Laurent expansion method and coordinate transformation, complex stress functions that represent the interaction of elliptical rigid inclusions arbitrarily distributed in the isotropic elastic matrix are constructed, and boundary conditions of every inclusion are satisfied. By circulation integrals, boundary equations are transformed into linear algebraic equations. Under the uniform tensile load at infinity, interfacial stress formulas, with numerical results and graphs, showing interfacial stress maxima varying with the shape of inclusions, were obtained. A comparison was made with other numerical results to demonstrate the superiority of the proposed model and accuracy of the solutions.