Papers by Keyword: Stress Test

Abstract: Stress corrosion cracking (SCC) is one of the reasons of failure of main gas pipelines. SCC appears in the form of the single and multiple cracks arising on an outer surface of a pipe. In work different types of the analysis of destruction of the pipeline having multiple cracks are presented. For the purpose of studying of a number of features of SCC by authors various researches were conducted: electrochemical researches, potentiodynamic measurements at various temperatures. With the help of potentiometric studiesit is shown that at low temperatures process of formation of a passive film is at a loss, however, with temperature increase processes of oxidation of metals proceed much quicker, at the same time decrease of their thermodynamic opportunity is observed. The nature of temperature effect is defined on oxidation rate of metals by temperature dependence of a kinetic constant of chemical reaction that is expressed by the Arrhenius equation.

Abstract: The last accidents of the NPP in Chernobyl and Fukushima give us the new inspiration to verify the safety level of the NPP structures. This paper presents the new requirements to test of the safety and reliability of the NPP structures due to the last accidents in the world. The risk assessment to verify of the safety and reliability of the NPP structures based on probabilistic and nonlinear analysis is presented. The uncertainties of the loads level (long-time temperature and dead loads), the material model (concrete cracking and crushing, behaviour of the reinforcement and liner), degradation effects and other influences following from the inaccuracy of the calculated model and numerical methods were taken into account in the LHS method. The results of the deterministic and probabilistic analysis of the NPP structures are presented.

Abstract: Design and construction of pile foundation in seaside zone face the specific geotechnical conditions. The in-situ geotechnical tests need to be conducted. The quality feature of the piles is assessed according to the results of in-situ small strain test, coring test and pile stress test. For different depth of rock and soil stratum and pile bearing layer, the trial pile stress distribution results and follow-up stress and settlement monitoring provide engineering parameters for design and pile-driving.

Abstract: In order to study the impact resistance capability of dump truck bodies floor, a simulation model of dump truck bodies floor and impact hammerheads made of metal materials were designed, and a strain test system of bodies floor under impact loading was established, a measurement of the stress of bodies floor model was made to obtain the law of stress variation about key point of truck bodies floor model. The research laid the foundation for the analysis of impact resistance capability of dump truck bodies floor using finite element method as well as provided a reference for the structural optimization of truck bodies floor.

Abstract: According to the structure and construction characteristics of PC continuous beam bridge and combined with the construction monitoring method of continuous beam bridge, this paper introduces the girder stress strain test technology and method of prestressed concrete continuous box girder bridge, also analyzes the various factors which affect the stress test. After monitoring LinGang big bridge, draw the conclusion through the analysis of its stress and strain.

Abstract: t has to face the fact that raw material cost is rising and the adhesive contain formadehyde in the furniture industry. Therefore, taking corrugated Chair as a breakthrough perspective was presented in order to meet 100% recyclable demand. With low carbon theory, design strategy was proposed based on analysis of the material and user requirements. Design location: the young people.The proposed design key point contains: fewer components and easy to assemble. Abstraction and simplification, single design and community combination, simulation of irregular things, dimension transuding, four design rules as important laws in industrial design were applied to explore reasonable morphology and structure.It put forward to appraise the design schemes from six aspects: attractive appearances, assembly processing, saving in material, proper ergonomic, and poly-functionality, fully collapsible for easy storage. According to stress test, experimental results show that the schemes are feasible and valid.

Abstract: The safety performance of bridge type grab ship unloaders are the main factors in the normal operation of a bulk cargo wharf. This article made a research of the stress test technology on the use of safety assessment on the structure of the bridge type grab ship unloader, through the dynamic stress test of ship unloader key parts of the structure under the use of the condition, analysis bridge type grab ship unloader safety performance is at ordinary times and maintenance and inspection needs to focus on the dangerous site.Stress test shows that the Maximum compressive stress is Point 7, its maximum dynamic compressive stress is 82.5MPa; while the maximum tensile stress occurs at point 11, its maximum dynamic tensile stress of 72.5MPa. After 17 years used, The force main parts (except former trolleys) of the ship unloader are basically the same as its design value.

Abstract: Hydraulic support is an important equipment of synthesis mechanization caving coal and safe production in modernization coal mine. According to the research object of ZF5000/16/28’s mould hydraulic support, stress distribution of dangerous parts is obtained by stress testing and ANSYS software. The relevant total displacement distribution rule and equivalent stress distribution rule of the type hydraulic support prototype were found. At the same time, reliability analysis of a single stent and stent system reliability prediction were carried out, which guides design and use of hydraulic support in theory better.

Abstract: In practice, surface residual stress test methods mainly contain the traditional semi-destructive central blind-hole method and the emerging non-destructive X-ray diffraction technology. The two methods process different measuring principle, which indirectly reflect material elastic deformation in macroscopic and microscopic fields respectively. Generally, comparative study of the feasibility of stress test scheme and accuracy of the measurements should be implemented experimentally. Surface residual stress levels and distributions of quenched high-strength aluminum alloy plate, shot-peened specimens and welded steel plate were tested by contrast using the two methods in this paper. The results show that both of the two surface stress measurement methods are effective and correct in most cases. But center blind-hole method is not suitable in measuring the gradient distribution with large stress gradient while X-ray method would be much affected by surface treatments and material microscopic inhomogeneity despite its capable of reflecting local details of the stress distribution. In engineering applications, proper test methods should be chosen according to the level and distribution of initial stresses. In addition, several methods are suggested to apply comparatively if conditions permitted.

Abstract: Based on normal elasticity equation, this paper has developed the calculation formula of face gear’s contact strength, bend strength and scuffing strength. This work put forward an analytical calculation method of face gear’s bend strength and constructed the analytical model. The result of bend strength of face gear was obtained by computer simulation. Based on the research, we designed and manufactured a suit of face gearbox. According to the tooth space trait, a method was represented to test bending stress of tooth by arrangement of sensing device in the tip end of the tooth of face gear. A test-bed has been set up with which the bending stress of tooth of face gear was carried out. The results showed that the maximal bending stress of test is similar to the simulation results by ANSYS.