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Rubber is the key component of a compression packer, which directly affects the success or failure of seals. Presently, the contact stress between the rubber and borehole walls is used as the main evaluation criterion for the sealing ability of the rubber of the compression packer. However, this evaluation criterion is imperfect. This study establishes the sealing performance and reliability evaluation system of a compression packer at 120°C. Considering the influence of time and temperature on the mechanical characteristics of rubber materials, the international advanced test technology was used to complete the uniaxial, planar and biaxial tensile tests and stress relaxation test for hydrogenated nitrile butadiene rubber (HNBR) of a compression packer under high temperature. Next, the hyperelastic and viscoelastic constitutive models of rubber materials based on high-temperature test data were established. Comprehensive sealing performance and reliability evaluation system for the compression packer rubber with compression rate, linear pressure, surface pressure and sealing performance coefficient were proposed. The evaluation system tested the rubber's stress relaxation effect on the rubber's sealing performance. The establishment of the evaluation system improved the shortcomings of the current packer-sealing performance evaluation system and provided a theoretical basis for the design and optimisation of the key structure of the packer-sealing system. Besides, based on the evaluation system, a platform for automatic structure simulation analysis and optimisation design of packer sealing system was developed and successfully applied to the actual design and optimisation process of packer. The system can effectively predict the sealing ability of the packer and guide field applications of the packer.

The mechanical properties of Sn-58 wt.% Bi solder with different amounts (0 wt.%, 0.05 wt.%, 0.1 wt.%, and 0.2 wt.%) of Ag-decorated multiwalled carbon nanotube (MWCNT) nanoparticles under 85°C/85% relative humidity environmental conditions for 0 h to 1000 h was investigated. Sn-58 wt.% Bi solder is a lead-free option for use in solder joints due to its low melting temperature and good creep resistance; however, it is brittle and has reliability issues. Ag-decorated MWCNT nanoparticles were used to improve these weaknesses of Sn-58 wt.% Bi solder. A ball shear test was performed using a bond tester to investigate the solder's mechanical properties. The microstructures of the solder joints and fracture mode were analyzed using a field-emission scanning electron microscope. The results demonstrated that the addition of Ag-decorated MWCNT nanoparticles to Sn-58 wt.% Bi increased the shear strength and fracture energy by approximately 15% and 14%, respectively, compared with Sn-58 wt.% Bi alone. After a high-temperature, high-humidity test for 1000 h, the shear strength and fracture energy of Sn-58 wt.% Bi with 0.1 wt.% Ag-decorated MWCNT nanoparticles were 13% and 21% greater than for Sn-58 wt.% Bi alone.

Inconel 625 alloys are widely applied for high-corrosion resistance and as high-efficiency materials in aeronautical, aerospace, chemical, nuclear, petrochemical, and marine industries. Although Inconel 625 alloys are excellent materials, they cannot be formed at room temperature owing to difficulties in processing. To improve the formability of Inconel 625, it is necessary to investigate its formability at a high-temperature range and its strain rate variation. In this study, high-temperature deformation behavior after forming was investigated. A high-temperature compression test was performed with a Gleeble 3500 testing machine at various temperatures (approximately 900–1200 °C) and strain rates (10 and 30 s−1) to obtain the high-temperature deformation characteristics of Inconel 625. Furthermore, high-temperature tensile tests were performed to measure elongations and reductions in the area of the Inconel 625 alloy. The tests focused on obtaining the flow stress data and optimal hot forging conditions under various strain rates and temperatures. The results of this research are expected to contribute to hot forming processes and to formability in hot extrusion and pilger processes.

Wire Arc Additive Manufacturing (WAAM) is one of the most appropriate additive manufacturing techniques for producing large-scale metal components with a high deposition rate and low cost. Recently, the manufacture of nickel-based alloy (IN718) using WAAM technology has received increased attention due to its wide application in industry. However, insufficient information is available on the mechanical properties of WAAM IN718 alloy, for example in high-temperature testing. In this paper, the mechanical properties of IN718 specimens manufactured by the WAAM technique have been investigated by tensile tests and hardness measurements. The specific comparison is also made with the wrought IN718 alloy, while the microstructure was assessed by scanning electron microscopy and X-ray diffraction analysis. Fractographic studies were carried out on the specimens to understand the fracture behavior. It was shown that the yield strength and hardness of WAAM IN718 alloy is higher than that of the wrought alloy IN718, while the ultimate tensile strength of the WAAM alloys is difficult to assess at lower temperatures. The microstructure analysis shows the presence of precipitates (laves phase) in WAAM IN718 alloy. Finally, the effect of precipitation on the mechanical properties of the WAAM IN718 alloy was discussed in detail.

Background Digital image correlation (DIC) is widely used as a noncontact optical deformation measurement method. However, optical DIC encounters difficulties when measuring displacement and strain at high temperatures, including false deformation caused by heat haze and image overexposure caused by intense thermal radiation. X-ray imaging is not affected by these factors, so the combination of X-ray imaging and the DIC algorithm (X-DIC) holds the potential for measuring deformation during high-temperature tests. Objective This study investigated the ability of X-DIC to measure deformation in high-temperature experiments, expand the applicable temperature range of X-DIC, and provide a reliable method for obtaining deformation measurements in high-temperature experiments. Methods A combination of X-ray digital radiography (DR) images and the DIC algorithm was used to measure deformation. Numerical experiments based on synthetic images were used to evaluate the measurement accuracy of X-DIC, and the influence of different DIC parameters on the measurement error was discussed. Ductile iron and C/SiC composites were subjected to tensile tests at different temperatures from ambient temperature to 1000 °C, and different deformation measurement methods were used to simultaneously measure the deformation of the samples to verify the accuracy of the X-DIC results. Results In the numerical experiments, the displacement measurement error of X-DIC is less than 0.02 px. The relative error between the X-DIC and blue-light DIC measurements of the tensile deformation of ductile iron at 500 °C is 0.65%. When the deformation of the C/SiC composite materials was measured at 1000 °C, the root mean square error (RMSE) of the strain data obtained by X-DIC and optical DIC was 1.12 × 10 –4 . Conclusions These results prove that X-DIC has high measurement accuracy. Compared with optical DIC, X-DIC is insensitive to high-temperature environments and provides alternative experimental methods for high-temperature deformation measurements.

The application of composite materials in the engine casings of aircraft engines offers a significant weight reduction effect. However, because the temperature of high-temperature components in advanced engines can exceed 350 °C, composite materials must possess excellent impact resistance under such conditions. Therefore, this paper investigates the high-speed impact failure mechanism of resin-based composite materials at room temperature and 350 °C. Ballistic impact tests were performed using 9 mm diameter steel projectiles traveling at a velocity of 522 m/s to evaluate the impact resistance of composite targets at room temperature and 350 °C. A cast copper heating ring was employed during the high-temperature tests to ensure the targets were heated to 350 °C. CT scans were used to assess the targets’ porosity before testing, and post-test analyses examined damage patterns to compare impact behavior at different temperatures. The results showed significantly more severe delamination in the composite targets under high-temperature conditions, with a markedly larger delamination area than observed at room temperature. The findings highlight that the elevated temperatures considerably weaken the interlaminar strength of resin-based composites, leading to increased delamination under impact loads. This study sheds light on the temperature-dependent performance of resin-based composites under high-velocity impacts, offering valuable insights and guidance for designing and optimizing protective composite structures in high-temperature environments.

The behavior of fiber reinforced polymer (FRP) composites at high temperature is a critical issue that needs to be clearly understood for their structural uses in civil engineering. However, due to technical difficulties during testing at high temperature, limited experimental investigations have been conducted regarding the thermal behavior of basalt fiber reinforced polymer (BFRP) composites, especially for the in-plane shear modulus of BFRP laminates. To this end, both an analytical derivation and an experimental program were carried out in this work to study the in-plane shear modulus of BFRP laminates. After the analytical derivation, the in-plane shear modulus was investigated as a function of the elastic modulus in different directions (0°, 45° and 90° of the load-to-fiber angle) and Poisson’s ratio in the fiber direction. To obtain the in-plane shear modulus, the four parameters were tested at different temperatures from 20 to 250 °C. A novel non-contacting digital image correlation (DIC) sensing system was adopted in the high-temperature tests to measure the local strain field on the FRP samples. Based on the test results, it was found that the elastic moduli in different directions were reduced to a very low level (less than 20%) from 20 to 250 °C. Furthermore, the in-plane shear modulus of BFRP at 250 °C was only 3% of that at 20 °C.

Aimed at the characteristics of high precision requirements and large environmental changes of the thrust and torque coupling test in the self-propulsion test of the ship model, the paper carries out the design of the instrument of the ship model test, the calculation of structural strength, the design of anti-jamming of the thrust and torque coupling, and the selection and realization of thrust and torque module. Based on the above, the instrument was calibrated with sensitivity coefficient, high and low temperature, and dynamic stability tests. Besides this, a self-propulsion test at the design speed point of a ship was carried out to verify the accuracy and environmental adaptability. From the static calibration result, the coefficient of determination is 1.0. The max zero drift of thrust and torque is 0.11% FS and 0.05% FS respectively from the low-high temperature test, and the max zero drift of torque under different revolutions is 0.23% FS from the dynamic test. In addition to the above, the max deviation between Maric-SP01 and R31 of thrust and torque is less than 0.78% and 0.65% respectively from the ship model self-propulsion test. So, in one word, the instrument has good reliability and accuracy and can meet the requirements of the ship model self-propulsion test.

Program of pattern evaluation of fixed electrical energy meters-alternating current and GB/T 17215 series of national standards for the examination of energy meter performance by the impact of temperature change, set up a variety of temperature-related test items. Systematic research is possible to conclude that temperature-related tests can be divided into two categories according to the test procedure: Hold at test temperature for a certain period of time, return to the reference temperature and then measure the relevant parameters; measurement of the relevant parameters immediately after a certain period of time at the test temperature. Relevant parameters include errors at different load points and daily timing error of the internal clock of the energy meter. Data processing is undertaken after the test mainly consists of deriving error shift and mean temperature coefficient. This automated calibration method allows you to freely set the test temperature, test duration, reference temperature, stabilization duration, detection parameters, test points and data processing according to the test requirements. The paper explains in detail the application of the automated calibration method to realize typical temperature dependence, test of time-keeping accuracy of the energy meter with temperature and climatic tests (high temperature test, low temperature test and durability test of accuracy) The method breaks the shackles of the traditional calibration method of fixed test temperature, fixed test points and fixed test duration. It can adapt to the development needs of different levels of pattern evaluation of energy meter and national standards, for the laboratory to realize automated testing to provide the basis for industry standards and product testing commissioned inspection.