65 results about "Thermo-mechanical fatigue" patented technology

An apparatus for and method of minimizing the thermo-mechanical fatigue of flip-chip packages. The interposer of the present invention, preferably comprising an organic polymer such as polyimide, contains apertures having conductive plugs inserted therein for joining a chip to a substrate in an electronic module utilizing flip-chip packaging. The interposer is selected to provide optimum spacing between the chip and substrate having a coefficient of thermal expansion adapted to the thermal cycling temperature extremes of the module components. The interposer may comprise an inner core with two adhesive outer layers which may comprise different materials to promote adhesion at their respective interfaces within a module. Conductive plugs are disposed within the apertures of the interposer comprising of a first and second solder or comprising a conductive plug having top and bottom surfaces coated with a conductive adhesive. Preferably, the first solder is disposed within an interior of the apertures and the second solder is disposed within an exterior of the apertures such that the first solder is between a first portion and a second portion of the second solder. Upon reflow, the second solder is reflowed while the first solder remains solid.

The invention relates to a thermal mechanical fatigue test system and method for performing hollow turbine blade superposed high-cycle vibration. The test system comprises a high/low-cycle load loading subsystem, a temperature load loading subsystem, a cooling subsystem and a load coordination control subsystem, wherein the high/low-cycle load loading subsystem is used for independently applying high/low-cycle loads to turbine blades which are stably clamped by a special fixture; the temperature load loading subsystem is used for heating assessment sections of the turbine blades; the cooling subsystem comprises a water cooling part and an air cooling part; the water cooling part is used for cooling in a test process; the air cooling part is used for coordinating a temperature cycle in the test and simulating cooling conditions inside the blades; and the load coordination control subsystem is used for controlling each system to operate in a coordinated manner. According to the test system disclosed by the invention, the stress field, temperature field and vibration conditions in the assessment section service process of the turbine blades and the cooling conditions inside the blades can be simulated, the thermal mechanical fatigue test for superposed high-cycle vibration of the turbine blades is performed, and a guarantee is provided for safe and reliable operations of aircraft engines.

The invention discloses a life prediction method used for a nickel-base superalloy blade under a thermal mechanical fatigue load. The problems of life prediction and joint representation of low cyclefatigue damage, creep damage and oxidation environment damage of the nickel-base superalloy blade under the TMF load are effectively solved; according to isothermal low cycle fatigue life data of nickel-base alloy under the condition of not causing high-temperature effects of creep, oxidation and the like, fitting is performed to obtain a strain life equation; in combination with a fatigue damagelinear accumulation theory, a fatigue damage model is obtained; a creep damage model is represented as temperature, stress and time functions; the oxidation environment damage is modeled based on an oxidation-cracking mechanism with a continuous oxidation layer at a crack tip; a continuous damage accumulation mechanism is adopted for the three models; and by virtue of stress, strain and temperature data of dangerous position points of the blade, accurate and reliable unified representation of fatigue, creep and oxidation interactive damage, and life prediction of a combined damage model to a nickel-base superalloy member under the thermal mechanical fatigue load is realized.

Material testing under variable heat and load while continuously monitoring crack formation is provided using an apparatus that permits thermal control somewhat uniformly over a conductive sample, while permitting a controlled load to be applied to the sample in tensional or flexural modes. Thermographic imaging of a sample in situ within a standard thermo-mechanical fatigue (TMF) test rig or other heat and load test apparatus is used to detect and monitor cracks as they form. A 360° sample view is possible. Image analysis software may identify, count and/or characterize cracks. Thermographic images may be analyzed to determine a sample temperature, e.g. for temperature feedback control. Essentially passive thermography is used with an inductive heating coil that surrounds at least 60% of a length of the sample, with at least two windings, the windings having thickness and pitch so that at least half the sample is in view.

A test facility includes a heat source to thermally load a test object being mechanically loaded by rotation imposed by a spin test rig. The heat source can be a quartz lamp controlled to provide a thermal load with a differing phase than the mechanical load. Testing cycles can be run for the test object, with impingement cooling permitting the removal of the thermal load between cycles. The test facility emulates operating conditions in a gas turbine engine to impose realistic thermal and mechanical fatigue stress on the test component.

The invention relates to a device and a method for testing thermo-mechanical fatigue. The device comprises a rotary bending fatigue loading device, a heating device for applying a temperature load to a fatigue sample, a sample surface gaseous environment control device and a temperature measurement device. Through the device and the method in combination with the conventional device and the conventional method for rotary bending fatigue and high-speed heating, the temperature load effect of different phase differences on the sample is ensured under the condition of rotary bending fatigue loading. The mechanical load of the fatigue sample is applied and controlled by the rotary bending loading device, while the temperature load is applied and controlled by the heating device and the temperature measurement device; and the phase difference of a temperature waveform and a mechanical load waveform is controlled by the number and the positions of the heating ends of the heating device. The thermo-mechanical fatigue testing device of the invention has the advantages of simple structure, low energy consumption and the capability of realizing rapid temperature rise and drop and accurate phase difference control between the mechanical load waveform and the temperature waveform.

A shape memory alloy thermal mechanical fatigue test device is used for being matched with an MTS tester to conduct a shape memory alloy thermal mechanical fatigue test. An MTS controller 2 controls the acquisition and processing of force and strain data. A sample chuck of the MTS tester is connected with a sample 8 to be tested through an insulating clamping device 10, the output end of a controllable electric heating power supply 4 is connected to the two ends of the sample 8 to be tested in a straddling mode, a temperature signal is input into the MTS controller 2 through a temperature sensor used for measuring the instant temperature of the sample to be tested, and a temperature controller 7 controls on-off of the power supply 4 to enable the sample to be tested to be at a set temperature. The test device for thermal mechanical fatigue study of a shape memory alloy material is provided, temperature rising and lowering circulation of the material can be achieved effectively, temperature rising inside and outside the material is even, insulation between the test device and a hydraulic tester is achieved, and synchronous acquisition of force, temperature and strain data is achieved.

Disclosed are novel nickel-base alloy compositions that may be cast as a single crystal or directionally solidified alloy consisting essentially of, by weight: 8-12% Cr, 10-14% Co, 0.3-0.9% Mo, 3-7% W, 2-8% Ta, 2.0-5.5% Al, 1.5-5.0% Ti, up to 2% Nb, less than 0.1% B, less than 0.1% Zr, 0.05-0.15% C, less than 0.5% Hf, 2-4% Re, 0.05-0.2% Si, up to 0.015% S, up to 0.1% La, up to 0.1% Y, up to 0.1% Ce, up to 0.1% Nd, up to 0.1% Dy, up to 0.1% Pr, up to 0.1% Gd, balance is Ni, and wherein (La+Y+Ce+Nd+Dy+Pr+Gd) is 0.001-0.1%. The compositions for the nickel-base superalloy have a balance between oxidation resistance, corrosion resistance, castability, and mechanical properties, such as creep resistance and thermo-mechanical fatigue resistance.

The invention relates to a turbine blade thermal mechanical fatigue test system. A motor is used for driving a wheel disc capable of installing turbine blades to form a rotating speed loading device.The blades are heated by a round induction heating coil, wherein the round induction heating coil is connected to a high-frequency induction heating furnace and is arranged in the middle of the turbine blade in a sleeved mode. The induction heating coil and the high-frequency induction heating furnace are connected by means of an insulating copper wire passing through a double-channel copper pipeand a slip ring electricity guide and to form a current loop. The centrifugal force generated by the high-speed rotation of the wheel disc is used for providing power for the cooling water circulation, so that the technical problems that heat source is loaded on the turbine blade, and the induction heating coil running at a high speed can be timely cooled are solved. The centrifugal force load andthe cross section working temperature field of the turbine blade in the working environment can be more truly simulated, so that the aero-engine turbine blade thermal mechanical fatigue test result is more accurate and reliable compared with the prior art.

The invention provides an equivalent method for predicting the thermo-mechanical fatigue life and relates to the field of fatigue strength. The method comprises the following steps: 1, using a finite element method for calculating out high temperature fatigue data of thermo-mechanical fatigue at the highest temperature and corresponding thermal strain data within a corresponding temperature range; 2, converting an original three-parameter power function energy method at the constant temperature into a three-parameter power function energy method containing thermal strain items by taking thermal strain into consideration; 3, comparing equivalent energy obtained by applying the improved three-parameter power function energy method to data obtained through finite element calculation with energy obtained by calculating data obtained through thermo-mechanical tests; 4, utilizing the improved three-parameter power function energy method for conducting prediction on the thermo-mechanical fatigue life; 5, in engineering, applying a dispersion band and standard deviation to the equivalent energy method and a stretching lagging energy model for measuring the capability of the model for predicting the life. A prediction result shows that the equivalent method can be used for better calculating the thermo-mechanical fatigue life.

The invention discloses an automobile headlamp structure fatigue life analysis method. The method comprises the steps that 1a, road spectrum data are collected and corrected; 1b, corrected road spectrums are simplified and calibrated; 2, environment temperatures in winter and summer are simulated respectively, and internal temperatures on the turn-on condition and the turn-off condition of a headlamp are simulated to obtain headlamp temperature field data on four conditions; the time scale between turn-on condition and turn-off condition of the headlamp is determined according to a market survey result, and temperature field combination data are established; 3, a headlamp assembly finite element model is established, thermo-physical properties and mechanical properties of all parts are input into the headlamp assembly finite element model, contact relations and assembly relations between all structures are defined, the temperature field combination data are imported, road spectrum simulation is applied, the thermo-mechanical coupling stress strain response of an automobile headlamp assembly structure within one cycle is calculated, and the thermo-mechanical fatigue life of the headlamp is calculated through fatigue analysis software. By means of the method, the fatigue life of the headlamp can be predicted at the design stage.

A test method for testing the thermal mechanical fatigue performance of a test material includes preparing a test specimen of the test material, wherein the test specimen has a base, and a rib extending outwardly from the base. The test specimen is thermally cycled through at least one test cycle. In each test cycle the rib is heated to a higher rib temperature and thereafter cooled to a lower rib temperature. The test specimen is evaluated for thermal mechanical fatigue damage.

The invention relates to a high-temperature large-load test fixture and test method for a turbine blade joggle joint structure, which can be used for test loading of thermal mechanical fatigue, creep-fatigue, low-cycle fatigue, creep and the like of the turbine blade joggle joint structure. The upper end and the lower end of the fixture are respectively connected with a fatigue testing machine through a clamping component, and the clamping components are connected with a turbine blade upper fixture and a turbine blade lower fixture through dovetail-shaped joggle joint structures; the turbine blade upper fixture is mainly composed of two components, a cold water channel is formed in the turbine blade upper fixture, a turbine blade is installed in an inner cavity formed by the two components, and the installation and positioning of the turbine blade and the blade upper fixture and the transmission of an axial load are achieved through a pair of inclined planes of the root extending section; the lower fixture is made of a high-temperature alloy material and is matched with a turbine blade tenon through a longitudinal tree-shaped mortise, and the blade joggle joint structure can be heated by using an induction heating coil. According to the invention, stable clamping of the turbine blade is realized, and the test requirements of applying a temperature load ranging from room temperature to 500 DEG C and a mechanical load from 0N to 150kN to the joggle joint structure can be met.

An article of manufacture has a body formed in part of a first metal alloy and in part of a second metal alloy, the second metal alloy having a thermal coefficient of expansion that is less than the thermal coefficient of expansion of the first metal alloy. A BOAS segment for a gas turbine engine is disclosed wherein the formation of cracks due to thermal mechanical fatigue in the body of the disclosed BOAS segment is minimized, if not eliminated, through a unique construction of the disclosed BOAS segment, whether original equipment manufacture or a repaired blade outer air seal. A method for manufacture of a BOAS segment and a method for modifying a BOAS segment are disclosed.

The invention discloses a circular large-dimension IGBT chip crimping packaging structure and a manufacturing method. The circular large-dimension IGBT chip crimping packaging structure comprises an emitting electrode end cover, emitting electrode molybdenum sheets, a gate spring needle assembly, gate metal, an emitting electrode molybdenum sheet positioning frame, flexible conductive metal thin sheets, emitting electrode metal, an IGBT chip, collector electrode metal, collector electrode molybdenum sheets with positioning holes, a collector electrode end cover and the like which are arrangedfrom the top to bottom in sequence. By adopting the crimping packaging structure, a fault sector region isolation method is simple, so that only the fault region sector conductive molybdenum sheets need to be changed into insulating sheets, and the gate metal specific connecting position on the surface of the chip is cut off; a device is subjected to two-sided heat dissipation through the collector electrode end cover and the emitting electrode end cover; metal bonding wires and a welding interface are omitted, so that the bottleneck of conventional device bonding point and welding layer fatigue failure can be eliminated, and relatively high resistance to thermal mechanical fatigue can be achieved; the interior of the device adopts symmetrical structural design, so that stray inductance ofeach sector region in the interior can be lowered, the stray inductance distribution can be consistent, the parasitic parameter of a module can be reduced, and the electrical performance of the device can be improved.

The invention discloses an aero-engine acceleration control real-time optimization method based on prolonging control. According to the method, in the acceleration control process of an aero-engine, the service life of the aero-engine is prolonged by reducing the thermal mechanical fatigue of the aero-engine in the acceleration process. The invention further discloses an aero-engine acceleration control real-time optimization device based on prolonging control. Compared with the prior art, the an aero-engine acceleration control real-time optimization method and device based on prolonging control have the beneficial effects that the effect of the thermal mechanical fatigue subjected by aero-engine blades is taken into consideration in the acceleration process, in the acceleration optimization purpose, rapid responding of the engine is taken into consideration, and moreover, the thermal mechanical fatigue life of the blades is guided into a target function. Thus, the engine can achieverapid responding, and meanwhile relatively long service life is achieved.

The invention pertains to a test apparatus and method for assessing thermo-mechanical fatigue related phenomena within a test material wherein a heat source, such as a laser beam is applied to a specimen consisting of a body of the test material, thereby introducing heat to a primary heat introduction zone on the surface of the body to cause local cyclic heating. As part of the cycle, heat is removed through a portion of the specimen surface sufficiently remote from the heat introduction zone to create a substantially spherical temperature gradient within the specimen resembling that of a point source on a semi-infinite body. A stress gradient results from local thermal expansion, thus thermo-mechanically cycling the material. As a result of the thermo-mechanical cycling, phenomena including thermo-mechanically induced creep, residual stress, changes in physical properties, crack initiation and crack growth may be observed within the material, and evaluated for scientific or engineering purposes. An optional background temperature control feature may also be included to raise the background temperature of the specimen during thermal cycling. Among many useful embodiments described herein, the test method may also be configured for non-destructive use on a component, wherein the local damage or crack growth due to thermal cycling is afterwards removed and the surface blended or otherwise reconditioned as required to restore component functionality and structural integrity.

The invention discloses a shaft torsional multi-axis variable-amplitude thermo-mechanical fatigue life prediction method based on material critical surface damage. The invention relates to the field of multi-axis thermo-mechanical fatigue strength theories. The method includes calculation of a multi-axis mechanical load cycle count, the critical surface angle of each load cycle, the critical surface pure fatigue damage of each load cycle, the total pure fatigue damage of the critical surfaces, stress on the critical surface of the material, an average differential critical surface load history, the critical surface equivalent creep stress of each section, the critical surface creep damage of each section, total creep damage of all critical surfaces, total non-pure fatigue damage of all critical surfaces, total damage of the critical surfaces and predicted service life. The proposed life prediction method can well predict the fatigue life of the alloy material under the shaft torsionalmulti-axis variable-amplitude thermo-mechanical loading.

The invention discloses a metal component thermal mechanical fatigue life prediction method based on different constraint conditions, and belongs to the technical field of material science and engineering application. The method comprises the steps that firstly, according to a service working condition, the load condition faced by a service component is obtained, a thermo-mechanical fatigue test of a metal material in a constraint state is designed and carried out, the relation between thermo-mechanical fatigue cycle hysteretic energy and a constraint coefficient is determined, a hysteretic energy model is established, and related parameters are obtained; according to the hysteretic energy accumulation damage model, the method for predicting the thermal mechanical fatigue life under different constraint conditions is established, and then the service time of the component under the actual service working condition can be deduced. According to the method, the thermal mechanical fatiguelife of the material can be accurately predicted by constraining a thermal mechanical fatigue acceleration test, and meanwhile, the method can also be used for evaluating the performance of a component under an actual service condition.

The invention relates to a strain-controlled thermal mechanical fatigue performance test method. The method comprises the following steps: firstly, carrying out testing to obtain thermal deformation data in a pure thermal cycle period; dividing the thermal cycle period into four parts, a temperature range of the I part being T0-Tmax, a temperature range of the II part being Tmax-T0, a temperaturerange of the III part being T0-Tmin, and a temperature range of the IV part being Tmin-T0; carrying out segmenting at the moment positions at which the thermal deformation rates change in the parts I,II, III and IV, and then, respectively solving the thermal deformation rate vth of each segment through linear fitting; calculating and determining the total deformation rate vtot of each segment according to the equation vtot=vm+vth, wherein the vm is the mechanical deformation rate required by the test; and finally, controlling a thermo-mechanical fatigue test system to apply a constant mechanical deformation rate vm to the test sample according to the total deformation rate vtot of each segmented test sample. According to the method, the probability that the sample is snapped or bent in advance is reduced, and the fatigue characteristic of the sample under the combined action of temperature and mechanical load at different phase angles can be reflected more accurately.

The invention relates to a high-low temperature test box capable of quickly changing temperature for a double-temperature-zone thermal mechanical fatigue test. The high-low temperature test box is used for a thermomechanical fatigue test of a glass transparent part. A box body (1) is arranged on a mechanical fatigue testing machine, a fatigue sample (2) penetrates through the upper and lower end faces of the box body (1) and is clamped between an upper clamp and a lower clamp of the mechanical fatigue testing machine, and the test box is characterized in that a partition plate (3) is arrangedin a test box (7) in the box body (1) to divide the space in the test box (7) into two independent temperature intervals (4), so that the transition surface and the opposite surface of the fatigue sample (2) are respectively positioned in the two independent temperature intervals (4), and the two independent temperature intervals (4) are sealed intervals. The problems that an existing high-low temperature test box for the fatigue testing machine is low in temperature changing speed and can only provide a single test temperature area are solved.