Special Test Equipment Research Articles

Simulations for the Development of Thermoelectric Measurements

In thermoelectricity, continuum theoretical equations are usually used for the calculation of the characteristics and performance of thermoelectric elements, modules or devices as a function of external parameters (material, geometry, temperatures, current, flow, load, etc.). An increasing number of commercial software packages aimed at applications, such as COMSOL and ANSYS, contain vkernels using direct thermoelectric coupling. Application of these numerical tools also allows analysis of physical measurement conditions and can lead to specifically adapted methods for developing special test equipment required for the determination of TE material and module properties. System-theoretical and simulation-based considerations of favorable geometries are taken into account to create draft sketches in the development of such measurement systems. Particular consideration is given to the development of transient measurement methods, which have great advantages compared with the conventional static methods in terms of the measurement duration required. In this paper the benefits of using numerical tools in designing measurement facilities are shown using two examples. The first is the determination of geometric correction factors in four-point probe measurement of electrical conductivity, whereas the second example is focused on the so-called combined thermoelectric measurement (CTEM) system, where all thermoelectric material properties (Seebeck coefficient, electrical and thermal conductivity, and Harman measurement of zT) are measured in a combined way. Here, we want to highlight especially the measurement of thermal conductivity in a transient mode. Factors influencing the measurement results such as coupling to the environment due to radiation, heat losses via the mounting of the probe head, as well as contact resistance between the sample and sample holder are illustrated, analyzed, and discussed. By employing the results of the simulations, we have developed an improved sample head that allows for measurements over a larger temperature interval with enhanced accuracy.

Structural Failure Analysis of Shaft of Wobbly and Attrited Testing Equipment

In order to research the fatigue strength of gasket which is with new composite material in one plane, we designed and manufactured special testing equipment. The material of shaft of testing equipment is 30CrMnSi. In the experiment, the 30CrMnSi shaft was broken into two parts by suddenly. By structural analysis, static analysis and heat treatment analysis for shaft, we get the reason of fracture for shaft finally. The problem solved make the test goes well and can help design and manufacture testing equipment in the future.

The response of the rider’s body to roll oscillations of two wheeled vehicles; experimental tests and biomechanical models

This paper deals with a research aimed to identify the biomechanical properties of the rider’s body from laboratory tests. Special test equipment has been developed; it is a motorcycle mock up driven by a hydraulic servo-actuator that generates oscillations in the range 0.5–10 Hz. When the rider rides the motorcycle mock up, a system of sensors measures the input motion and the response of the rider’s body. The response of the rider’s body is represented in the frequency domain by means of frequency response functions: the motion frequency response function describes the lean motion of the rider’s trunk, the torque frequency response function describes the torque applied by the rider on the handlebars. The measured frequency response functions are used for identifying the parameters of lumped mass biomechanical models, which are suited to integration with the multi-body model of the motorcycle. Many experimental results are presented and discussed. Various biomechanical models are evaluated in terms of capability of reproducing the measured frequency response function. A good fitting of the motion frequency response function is achieved by means of a three-degrees-of-freedom model of the rider’s trunk, whereas a good fitting of the torque frequency response function is achieved by means of a five-degrees-of-freedom model of trunk and arms.

헬리콥터용 보조동력장치 고공성능에 관한 실험적 연구

An APU(Auxiliary Power Unit) for helicopters has been developed in Korea and tested at the AETF(altitude engine test facility) in KARI(Korea Aerospace Research Institute) for the purpose of the military qualification. A cell correlation test was performed before the official test, and the results are within the tolerance. The APU has the capability of supplying electric power as well as compressed air to the helicopters. It was tested at bleed extraction conditions, electric power extraction conditions, and maximum continuous concurrent power conditions within the entire helicopter flight envelop. Some special test equipments were implemented for the measurement of air flowrate, electric power and so on. The tests were successfully performed and their results satisfy the requirements of the helicopters.

한국형 기동헬기 자체진단 시험 설계 및 입증

임무탑재장비 체계는 한국형 기동헬기의 임무 수행을 위해 전자장비 구성품들을 통합한 항공전자 체계다. 자체진단 시험은 숙련된 요원, 특수 시험장비의 필요성을 감소시키주며 체계의 정비를 위한 비가동 시간을 줄여준다. 갈수록 복잡성이 증가하고 있는 항공전자 장비에 대한 자체진단 시험 기능의 필요성이 더욱 커지고 있다. 본 논문은 한국형 기동헬기 항공전자 체계에 구현한 자체진단 시험 설계 및 입증에 대해 설명한다. Mission Equipment Package(MEP) system is a collection of avionic components that are integrated to perform the mission of the Korean Utility Helicopter(KUH). Built In Test(BIT) reduces the need for skilled personnel and special test equipment, and reduces maintenance down-time of system. The increasing complexity of avionics equipments has resulted in an increased need to provide BIT functions. This paper describe the development and verification for the KUH MEP system BIT.

9.7.2 “Looking Forward” Engineering Systems Integration

AbstractEngineering systems integration involves dealing with a multiplicity of challenges. Different disciplines must be balanced, the work of several teams must be coordinated, and the issue of units that are necessary but not available on time must be handled; special test equipment must be designed, hubs and stubs must be prepared; and risks that are liable to occur during integration must be assessed and prevented – to name just a few of the tasks. All these problems and difficulties result in schedule delays and unplanned expenses. We present a structured methodology for building an integration preparation plan and thereafter guiding the actual integration. The methodology is based on the “V” model for systems engineering. The left side of the “V” represents the design stage and the right side represents the integration stage. The “looking forward” methodology follows the development steps and at each step looks forward to the relevant integration step, anticipating what may be required for successful integration. This action creates versatile integration tools that are flexible enough to absorb unexpected variations in the project.

무기체계 정비성 향상을 위한 BIT 설계 및 검증 방안

Built-In-Test is a design feature in more and more advanced weapon system. During development test and evaluation(DT&E) it is critical that the BIT system be evaluated. The BIT system is an integral part of the weapon system and subsystem. Built-In-Test assists in conducting on system and subsystem failure detection and isolation to the Line Replaceable Unit(LRU). This capability reduces the need for highly skilled personnel and special test equipment at organizational level, and reduces maintenance down-time of system by shortening Total Corrective Maintenance Time. During DT&E of weapon system the objective of BIT system evaluation is to determine BIT capabilities achieved and to identify deficiencies in the BIT system. As a result corrective actions are implemented while the system is still in development. Through the use of the reiterative BIT evaluation the BIT system design was corrected, improved, or updated, as the BIT system matured.

Evaluation of Delayed Fracture Characteristics of High-strength Bolt Steels by CSRT

Delayed fracture is affected by two parameters: stress and hydrogen. Hydrogen enters the material from the environment as a result of corrosion. Generally, it takes a relatively long time, so that fracture occurs with a time lag after loading. The delayed fracture occurs when the driving force (S-H)E becomes greater than the material resistance (S-H)C. Extensive research has been carried out to evaluate the material resistance against delayed fracture using the constant load test (CLT) and slow strain rate test (SSRT). Recently, the author has developed a test method called conventional strain rate test (CSRT). In CSRT, hydrogen, at a content corresponding to the accumulated hydrogen concentration in CLT and SSRT, is introduced uniformly into the specimen and loading is applied at a conventional strain rate with negligible hydrogen diffusion. The advantage of CSRT is that it requires no special testing equipment and the testing time is very much shorter than those of the previous test methods. The principle, test procedure and some experimental results of CSRT are discussed in this paper.

Analysis of In-Service Lubricating Grease

Abstract The analysis of in-service lubricating fluids is a useful tool in determining the state of both the fluid and the equipment being lubricated. Many laboratories provide analysis services for in-service lubricating fluids. The results of the analyses performed are often tracked over time to allow for the observation of trends in the test results. The analysis of in-service lubricating grease is a more challenging task; since the amount of grease in many applications is quite small, the grease may be partially or totally replaced each time new grease is added, and access to the lubricated contact zone may be difficult. Many commercial in-service lubricant analysis laboratories lack the specialized test equipment required for grease analysis, so that type of analysis is performed by a limited number of laboratories, primarily those of the grease manufacturers. Various techniques are employed to determine both the macro and micro condition of in-service lubricating grease. The strengths and weaknesses of those techniques are discussed herein.

Cryogenic fatigue behaviour of steel-concrete composite structures

Aiming to the application of steel-concrete composite structures in extremely cold zones, a special cryogenic test equipment was developed to simulate the temperature environment along Qinghai-Tibet railway, and cryogenic fatigue tests were carried out on 10 specimens composed of 14MnNbq steel, Φ22 studs and C50 concrete. Taking temperature variation and steel rolling direction into consideration, fatigue failure mode and fatigue behaviour of the composite structures under low-temperature were well studied. Test results were compared with that under normal temperature. Results showed that composite structures performed better cryogenic fatigue performance with temperature ranging from 0°C to -50 °C, the lower the temperature is, the longer the fatigue life tends to be. This is due to the excellent cryogenic fatigue performance of 14MnNbq steel. Steel rolling direction has important influence on the fatigue behaviour of composite structures, specimens with along rolling steel girders showed longer fatigue life than those with transverse rolling steel girders. Welding Φ22 studs on 14MnNbq steel girders showed no influence on the material quality of 14MnNbq steel. For safety purpose, fatigue bearing capacity of Φ22 studs in Qinghai-Tibet railway composite bridges was suggested to be 80% of that under normal temperature.

Measurement of the Incident Sound Power in Ducts and Effect Factors Analysis

Based on two-microphone transfer function method, the measuring method of incident sound power in duct is introduced, The special test equipment is built, and the test and measurement program of incident sound power in duct is written, and effect factors of measurement are analyzed. Results are shown that temperature, flow velocity, microphone spacing deviation and complex reflection coefficient influences less on the program. Transmission loss of perforated tube muffler with no flow is measured using the program, comparison is carried out with results of finite element method, they agrees with well, and with flow sound power of flow regeneration from the muffler is also done, an important foundation is provided for quantitative study on occurring mechanism flow regenerated noise and enhancing attenuation performance of muffler.

星载调焦机构地面专检设备设计

To ensure the test for incorporate design of satellite platform and payload focusing mechanism on the ground to be reliable and valid,the mechanism of the special test equipment was studied.This paper analyzes the needs of the ground special test equipment,and with the combination of existing mature technologies,designs a focusing mechanism adjustment special test equipment,and implements the experiment of focusing mechanism.At last,this paper shows the location and speed test result.The test results show that the special test equipment meets the ground experiment requiements.

Design and Stimulation of Hydraulic Servo System for Vehicle Test Equipment for Rubber Shock Absorber

Development of special rubber shock absorber test equipment for vehicle will become very important, this equipment can test and analysis of dynamic characteristics for rubber shock absorber.The paper discusses the problem on optimum design of electro-hydraulic servo system which drives the vibration set. A closed system for controlling mechanical position or motion using feedback from the electro-hydraulic servo valve of the device as an input has been used in hydraulic servo system. The maximum region of design parameters has been defined for hydraulic servo cylinder as a core element of the electro-hydraulic exciting system. Established the mathematical model of the system, and the dynamic characteristics of the hydraulic servo cylinder are investigated by utilizing the simulation software MATLAB. The results of computer emulation show that this method is practical.

Corrosion Fracture of Structural Metallic Materials: Effect of Electrochemical Conditions in Crack

Abstract: The work is a compressed review based on the summarised results and the original approach for study of corrosion crack growth, taking into account local electrochemical conditions in the crack tip, which was developed at the Karpenko Physico‐Mechanical Institute of NASU. The model scheme of the pre‐fracture zone in the corrosion crack tip, which can be defined by the local values of pH of solution, electrode potential of metalEand stress intensity factorKIis proposed. For its realisation, the special method and testing equipment for corrosion crack growth study and local electrochemical measurements in the crack were developed. The variation of the electrochemical conditions in corrosion cracks was studied, and it has been found that some stabilised levels of the pH andEvalues can be achieved in the tip of a non‐propagating and a propagating crack under static and cyclic loading during of exposure time. On this ground, the method for forecasting of the threshold stress intensity factorKISCCunder stress corrosion cracking was proposed using these characteristic values of pH andE. This method was also adopted for the determination of the threshold stress intensity factorKthunder corrosion fatigue. The special method for determining corrosion fatigue crack growth rate diagrams based on consideration of extreme electrochemical conditions in the crack tip was developed. It has been proven that such diagrams reflect the extreme influence of the environmental factor on corrosion fracture of material, and they may be recommended as the base for the remaining lifetime calculation of the structural elements exploited under environmental conditions.

Software Design and Implement of Test System of a Certain Radar Transmitter Based on the 1553B Bus

A certain type of radar was equipped in the main fighter jets. It is main equipment which can ensure the completion of the task of the fight in the air. But at present, this type of radar transmitter outside the room does not have special test equipment and the manual testing process is also more complicated. So, to achieve rapid testing of this transmitter for technician and improve the measurement’s accuracy, need a new system. In this new system used bus control technology, virtual instrumentation technology and database technology. Besides these, brought them to combine organically, then we get the system with fault diagnosis, detection intelligently and the test database. In order to achieve test and communication with radar transmitters, the system used the MIL-STD-1553B bus as a control bus, the USB bus as a program-controlled instrument control bus and in LabWindows/CVI 8.5 development environment designed software of the system. After a trial showed that the system reached the requirements of the test specification.

화학적 방법에 의한 나노시멘트 개발에 관한 기초 연구

21세기에 접어들면서 IT, BT, NT, ET 등 첨단 산업은 하루가 다르게 발전하고 있으며, 이러한 추세에 맞추어 시멘트 산업에서도 많은 변화가 진행되고 있다. 또한 시멘트 산업은 에너지 다소비형이며 석회석을 원료로 하고 있어 지구온난화의 주범인 CO2를 배출하여, 환경문제로 인해 가까운 시기에 큰 어려움을 겪을 것으로 예상되고 있다. 이 연구에서는 시멘트 제조과정 중 소성과정에서의 CO2 발생을 방지하고, 나노 크기의 입자를 시멘트화 함으로써 구조적 치밀성을 유지하여, 고강도화내구성에 유리한 건설재료를 개발하기 위한 일환으로 기존 소성과정을 통한 시멘트 제조 방식과 달리, 화학적 방법을 통해 Bottom-up 방식으로 나노 크기의 새로운 개념의 건설재료를 개발하는데 그 목적이 있다. 시멘트 화학성분비에 착안하여 실리카, 알루미나 그리고 Ca 이온을 주재료로, 인공적으로 나노시멘트 분말을 합성하여 입도분석, SEM, EDX를 통해 그 재료적 특성을 파악하고, 모르타르를 제조하여, 강도특성을 측정하였다. 그 결과 평균 168 nm 크기의 나노 입자를 제조 할 수 있었으며, 적정 배합비의 모르타르의 7일 압축강도가 53.9 MPa로 측정되는 등 충분히 건설용 재료로서의 사용이 가능할 것으로 판단되었으나, 건설 분야로 응용을 위한 기초연구로써 보다 많은 연구가 수행되어야 할 것으로 판단된다.

Seismic performance of a full-scale, reinforced high-performance concrete building. Part I: Experimental study

Full-scale tests provide valuable information on the characteristics of building structures that can be used to evaluate design methods, to calibrate modelling techniques, and to determine damage corresponding to loading levels. These tests are scarce due to the enormous requirements in testing space and specialized testing equipment. The seismic behaviour of a full-scale, two-storey, reinforced high-performance concrete building designed with moderate ductility detailing is evaluated by pseudo-dynamic testing, during which increasing seismic loads are applied, resulting in increasing levels of permanent damage to the structure. To monitor the level of damage, a series of successive forced-vibration tests are also carried out at each step of the process and are used to track changes in the key dynamic properties of the building. The paper presents the design of the test structure according to the new edition of the CSA A23.3-04 Design of concrete structures standard, the series of pseudo-dynamic tests simulating different levels of earthquake excitation consistent with the 2005 edition of the National building code of Canada, and the evaluation of the performance of the building. It is shown that the detailing requirements of CSA A23.3-04 are more than adequate to provide the ductility and overstrength expected.

Seismic performance of a full-scale, reinforced high-performance concrete building. Part II: Analytical study

Full-scale tests provide valuable information on the characteristics of building structures that can be used to evaluate design methods, to calibrate modelling techniques, and to determine damage corresponding to loading levels. These tests are scarce due to the enormous requirements in testing space and specialized testing equipment. The seismic behaviour of a full-scale, two-storey, reinforced high-performance concrete building designed with moderate ductility detailing is evaluated by pseudo-dynamic testing, during which increasing seismic loads are applied, resulting in increasing levels of permanent damage to the structure. This paper presents the analytical predictions of the test results using a global force–displacement parameters approach and a refined approach, half-way between global modelling and finite element modelling, using force–strain parameters and damage mechanics principles. Identification of the parameters required to describe the response parameters are presented together with a description of the numerical procedures used in each approach. It is shown that the predictions are in good agreement with the test results. Advantages and disadvantages of each approach are highlighted in the context of performance-based analysis and design.

Vapor Adsorption Index for Expansive Soil Classification

A laboratory index defined as gravimetric water content at ambient relative humidity of 75% (w75) is proposed for qualitatively classifying the swelling potential of clays and clayey soils (e.g., low, moderate, high). The methodology is calibrated by comparison with existing plasticity-based and suction-based classification methodologies for a series of natural clays from Missouri and Colorado and clay mixtures prepared to represent a wide range of swelling potential. Procedures are described for obtaining w75 by placing samples in the headspace of an environmental chamber maintained under controlled humidity using a saturated NaCl solution. The proposed methodology has potential advantages over existing expansive soil classification methods because a large number of samples may be tested concurrently, no specialized testing equipment is required, and testing procedures may be readily automated. Measurements may be obtained in as little as 3–5days with coefficients of variation ranging from 5 to 25%.

관성 센서를 이용한 휴머노이드 로봇용 3축 자세 추정 알고리듬 개발

In this paper, a small and effective attitude estimation system for a humanoid robot was developed. Four small inertial sensors were packed and used for inertial measurements(3D accelerometer and three 1D gyroscopes.) An effective 3D pose estimation algorithm for low cost DSP using an extended Kalman filter was developed and evaluated. The 3D pose estimation algorithm has a very simple structure composed by 3 modules of a linear acceleration estimator, an external acceleration detector and an pseudo-accelerometer output estimator. The algorithm also has an effective switching structure based on probability and simple feedback loop for the extended Kalman filter. A special test equipment using linear motor for the testing of the 3D pose sensor was developed and the experimental results showed its very fast convergence to real values and effective responses. Popular DSP of TMS320F2812 was used to calculate robot's 3D attitude and translated acceleration, and the whole system were packed in a small size for humanoids robots. The output of the 3D sensors(pitch, roll, 3D linear acceleration, and 3D angular rate) can be transmitted to a humanoid robot at 200Hz frequency.