5 results about "Thermo-mechanical fatigue" patented technology

The present application relates to the field of material science and engineering application technology, specifically to a kind of metal material thermal mechanical fatigue life fast prediction method based on hysteresis energy density.First, hysteresis curve is used to calculate hysteresis energy density, then the quantitative relationship between shape coefficient, stress variation range and plastic strain range between low cycle fatigue and thermal mechanical fatigue is used, to achieve the purpose of predicting thermal mechanical fatigue hysteresis energy density under the same mechanical strain amplitude by low cycle fatigue, finally, energy accumulation damage model is used to predict thermal mechanical fatigue life.The method carries out two groups of experiments for low cycle fatigue and thermal mechanical fatigue respectively, realizes the prediction of thermal mechanical fatigue life under different mechanical strain amplitudes by low cycle fatigue, establishes the correlation between low cycle fatigue and thermal mechanical fatigue by using the similarity between them in the process of cyclic loading, effectively reduces the experimental amount required for thermal mechanical fatigue life evaluation, and is applied to the thermal mechanical fatigue life prediction of high-temperature alloy and vermicular cast iron and other metal materials.

This invention relates to the field of chip performance monitoring technology, and discloses a method for monitoring and evaluating the performance of chips throughout their entire lifecycle based on big data. This method first extracts key physical characteristics of each bare die at the manufacturing stage, generates individual chip quality factors, and writes them into a one-time programmable memory area. Then, at the application stage, it collects the junction temperature of each layer in real time, calculates the vertical temperature gradient vector and local absolute temperature, and constructs a thermo-coupled instantaneous interface mechanical damage rate model based on the quality factors to quantify the instantaneous interface mechanical damage rate. Furthermore, it introduces a business weight coefficient to couple electrical wear with cumulative thermo-mechanical fatigue damage, calculating the chip's remaining health. Finally, based on the health warning threshold, it executes a vertical wear balancing strategy to migrate the data of damaged layers to a safe level. This invention solves the problem that traditional chip performance monitoring cannot detect the risk of microscopic thermal mismatch within the stacked structure, and avoids sudden physical failures of the chip through proactive physical load redistribution.

The application discloses a thermal-mechanical fatigue crack propagation rate testing method based on rigidity and crack tip strain field, comprising the following steps: firstly, a relationship function between normalized crack length and normalized rigidity is established through finite element calculation; secondly, DIC speckle preparation is carried out for observing crack propagation and strain field analysis; then, a thermal-mechanical fatigue test is carried out, crack length is calculated based on rigidity change results of the test, an a-N relationship curve is drawn combined with DIC synchronous observation results, and comparative analysis is carried out; finally, crack propagation rate is calculated through a three-point moving average secant method, and the size of a plastic zone at a crack tip is determined according to DIC strain field analysis, so that the accurate test of the crack propagation rate is realized. The application can effectively test the fatigue crack propagation behavior under the thermal-mechanical coupling effect, and accurately obtain the thermal-mechanical fatigue crack propagation rate combined with the crack tip strain field measurement method, so as to provide test data support for damage tolerance design and structure integrity evaluation of high-temperature pressure-bearing equipment.

This application provides a system and method for regulating the hysteretic heat generation of rubber. First, under preset dynamic thermomechanical fatigue test conditions, a correlation model is established between the rubber's loss factor and dynamic heat generation performance, and a target range for loss factor regulation is determined based on the target heat generation performance. Next, based on the target range, the internal structure of the rubber is synergistically regulated by adjusting the rubber's formulation or process to change its loss factor. Then, standard dynamic thermomechanical analysis tests are performed on the regulated rubber samples to obtain its loss factor data, and its predicted heat generation performance is evaluated based on the correlation model. Finally, for rubber samples whose predicted heat generation performance meets the requirements, dynamic thermomechanical fatigue tests are conducted under the preset fatigue test conditions, and the hysteretic heat generation performance is ultimately verified by measured temperature rise or heat generation data. The above scheme can achieve precise regulation of the hysteretic heat generation of rubber.

This application discloses a heat-resistant eutectic Al-Si alloy material, which is obtained by adding strengthening elements Cu, Mg, Ni and microalloying elements Ti, Sc, and Zr to a eutectic Al-Si alloy and then subjecting it to ultrasonic treatment during the alloy solidification process. This application also provides a method for preparing the heat-resistant eutectic Al-Si alloy material. By controlling the formation of a nano-scale high-temperature stable precipitate phase, the thermomechanical fatigue performance and service performance of the Al-Si alloy material are improved; this addresses the technical problem that excessive Cu and Ni additions increase the volume fraction of intermetallic phases in the alloy microstructure, leading to increased brittleness and a mismatch between low-temperature plasticity and high-temperature strength, which is detrimental to the alloy's insufficient thermomechanical fatigue life during service.