A thermal-mechanical coupling test method for cylinder head simulation parts

Abstract

The present invention belongs to the technical field of cylinder head thermal-mechanical coupling testing and provides a method for thermal-mechanical coupling testing of a cylinder head simulation component, comprising: construction of a thermal-mechanical coupling fatigue test bench, acquisition of whole-machine test data, determination of preload, construction of a temperature load cycle curve, construction of a mechanical load cycle curve, curve fusion, acquisition of stress-strain data, determination of the coupling period, collection of crack data, thermal-mechanical coupling fatigue life recording, and data integration. By constructing a thermal-mechanical coupling fatigue test bench, the present invention shortens the heating time and accelerates the testing process; by fusing the temperature load cycle curve and the mechanical load cycle curve, it simulates the thermal-mechanical coupling effect of the cylinder head under actual operating conditions; by using four different load conditions, it provides more comprehensive analysis and data support; and by designing a cylinder head nose bridge area simulation component with cooling water channels, it more accurately simulates the actual operating state of the cylinder head, improving the accuracy and representativeness of the test results.

Description

Technical Field

[0001] The invention relates to the technical field of cylinder head thermal-mechanical coupling testing, in particular to a cylinder head simulation component thermal-mechanical coupling testing method. Background Art

[0002] The cylinder head is one of the key structural components of an internal combustion engine. It is used to seal the upper part of the cylinder and, together with the piston top and cylinder wall, form the combustion chamber. The cylinder head has an extremely complex structure, with intake and exhaust valves, valve guide holes, etc. machined on it, and internally cast cooling water channels, intake and exhaust pipes, and parts of the combustion chamber. When the internal combustion engine is operating, the cylinder head works in a very harsh environment and is subjected to very complex stress conditions. It not only needs to withstand mechanical loads such as the bolt preload generated during the internal combustion engine assembly process, but also the thermal load generated by gas combustion and the gas explosion pressure load. At the same time, due to the presence of cooling water channels, factors such as the uneven distribution of the coolant flow path can also lead to complex distributions of temperature and stress fields inside the cylinder head.

[0003] During service, cylinder heads face the complex coupling of multiple physical fields, including thermal, fluid-solid interaction. However, traditional testing methods face inherent limitations in addressing these challenges, including high costs, lengthy test cycles, complex operational procedures, and limited accuracy and precision. Patent CN106610355A discloses a thermal engine fatigue testing method and testing equipment. This invention provides a thermal engine fatigue testing method comprising the following steps: setting load parameters; controlling the surface temperature of the specimen to cycle within a set temperature range to apply a thermal load to the specimen; applying a mechanical load to the specimen based on a set functional relationship between mechanical load and temperature; and terminating the test after a set number of loading cycles. This method simultaneously controls the application of both the thermal and mechanical loads, achieving a corresponding relationship between the two, thereby more accurately simulating fatigue damage to the specimen material under the combined effects of mechanical and thermal loads. This comprehensive testing method offers a short test cycle, high precision, and good controllability. However, it lacks targeted design for the specific area of ​​the cylinder head nose bridge, particularly given the complex mechanical loads in this area, including the influence of multiple loads such as bolt preload and gas burst pressure. In addition, this technology only focuses on the correlation of numerical values ​​in terms of the correspondence between temperature load and mechanical load, and fails to fully consider the working sequence and phase difference between the mechanical load application equipment and the heating system. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a thermal-mechanical coupling test method for cylinder head simulation parts. By constructing a thermal-mechanical coupling fatigue test bench, the heating time is shortened and the test process is accelerated; by integrating the temperature load cycle curve and the mechanical load cycle curve, the thermal-mechanical coupling effect of the cylinder head under the actual working environment is simulated; and through four different load conditions, more comprehensive analysis and data support are provided.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for thermal-mechanical coupling testing of a cylinder head simulation component, comprising:

[0007] A thermal-mechanical coupling fatigue test bench is built based on the cylinder head nose bridge area simulation part; the thermal-mechanical coupling fatigue test bench includes: a fixture, a mechanical load applying device, an electromagnetic induction heating device, a thermocouple, a fan, a stress and strain sensor, a displacement sensor and a control unit; the fixture is used to fix the cylinder head nose bridge area simulation part through bolts and a plate; the cylinder head nose bridge area simulation part is T-shaped; the interior of the cylinder head nose bridge area simulation part is a hollow cooling water channel; the electromagnetic induction heating device is used to heat the fire surface at the bottom of the cylinder head nose bridge area simulation part; the thermocouple is used to collect temperature data of the target observation point; The fan is used to control the cooling rate of the cylinder head nose bridge area simulation part by adjusting the wind speed; the mechanical load applying device is used to apply a mechanical load to the cylinder head nose bridge area simulation part; the mechanical load includes: gas explosion pressure and the pre-tightening force of the bolt; the stress and strain sensor is used to collect stress data and strain response data of the cylinder head nose bridge area simulation part under the mechanical load; the displacement sensor is used to collect deformation data of the cylinder head nose bridge area simulation part under the mechanical load; the control unit is used to adaptively control the operating status of the mechanical load applying device and the electromagnetic induction heating device;

[0008] Collecting whole-machine test data of the cylinder head nose bridge area simulation component under four load conditions based on the thermal-mechanical coupling fatigue test bench; the whole-machine test data includes: maximum temperature, minimum temperature, maximum burst pressure, and the burst time of the maximum burst pressure; the four load conditions include: 25% load rate, 50% load rate, 75% load rate, and 100% load rate;

[0009] determining the preload force according to the maximum burst pressure;

[0010] constructing a temperature load cycle curve according to the maximum temperature and the minimum temperature;

[0011] constructing a mechanical load cycle curve according to the preload force and the burst moment;

[0012] The temperature load cycle curve and the mechanical load cycle curve are combined using a preset mapping formula to obtain a temperature-mechanical cycle curve;

[0013] Using the mechanical load applying device, a thermal-mechanical coupling fatigue test is performed on the cylinder head nose bridge area simulation part to obtain stress-strain data; the stress-strain data includes: a maximum stress value and an average stress value;

[0014] 100 cycles of the thermal-mechanical coupling fatigue test are determined as one coupling cycle;

[0015] After each coupling cycle, collecting crack data of the cylinder head nose bridge area simulation part;

[0016] When the crack data reaches a preset failure boundary, stopping the thermal-mechanical coupling fatigue test and recording the thermal-mechanical coupling fatigue life;

[0017] The temperature-mechanical cycle curve, the crack data, and the thermal-mechanical coupling fatigue life are integrated to obtain test results.

[0018] Preferably, the failure margin is 5 mm.

[0019] Preferably, the calculation formula of the preload force is: P0 = (1.25-2)πR 2 P max ; Wherein, P0 is the preload force; P max is the maximum burst pressure; R is the average radius of the sealing zone.

[0020] Preferably, the mapping formula is: Δt1=n×Δt2; wherein Δt1 is the temperature cycle duration of the temperature load cycle curve; Δt2 is the mechanical cycle duration; and n is the cycle proportional coefficient.

[0021] Preferably, the cooling method of the thermal-mechanical coupling fatigue test bench is forced convection cooling.

[0022] The present invention discloses the following technical effects:

[0023] The present invention provides a thermal-mechanical coupling test method for a cylinder head simulation component. By constructing a thermal-mechanical coupling fatigue test bench, the defects of slow heating and experimental time in conventional methods are solved, and the test process is shortened. By integrating temperature load cycle curves and mechanical load cycle curves, the problem of single test direction in conventional methods is solved, and the thermal-mechanical coupling effect simulation of the cylinder head under actual working environment is realized. By adopting a cylinder head nose bridge area simulation component with a cooling water channel, the defect of conventional equivalent simulation components ignoring the water channel structure is solved, and a coupling test that is more in line with real conditions is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a thermal-mechanical coupling test flow for a cylinder head simulation component according to an embodiment of the present invention;

[0026] Figure 2 A flow chart of a thermal-mechanical coupling test of a cylinder head simulation component provided by an embodiment of the present invention;

[0027] Figure 3 Schematic diagram of a thermal-mechanical coupling test bench provided in an embodiment of the present invention;

[0028] Figure 4 This is a temperature-mechanical cycle curve provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The purpose of the present invention is to provide a thermal-mechanical coupling test method for a cylinder head simulation component. By constructing a thermal-mechanical coupling fatigue test bench, the heating time is shortened and the test process is accelerated. By integrating temperature load cycle curves and mechanical load cycle curves, the thermal-mechanical coupling effect of the cylinder head under actual working conditions is simulated. Through four different load conditions, more comprehensive analysis and data support are provided.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 This is a schematic diagram of the thermal-mechanical coupling test flow of a cylinder head simulation component provided by an embodiment of the present invention. Figure 2 The flow chart of the thermal-mechanical coupling test of the cylinder head simulation part provided by the embodiment of the present invention is as follows: Figure 1 and Figure 2 As shown, the present invention provides a thermal-mechanical coupling test method for a cylinder head simulation component, comprising:

[0033] Step 100: Build a thermal-mechanical coupling fatigue test bench based on the cylinder head nose bridge area simulation piece; the thermal-mechanical coupling fatigue test bench includes: a fixture, a mechanical load applying device, an electromagnetic induction heating device, a thermocouple, a fan, a stress and strain sensor, a displacement sensor, and a control unit; the fixture is used to fix the cylinder head nose bridge area simulation piece through bolts and a plate; the cylinder head nose bridge area simulation piece is T-shaped; the interior of the cylinder head nose bridge area simulation piece is a hollow cooling water channel; the electromagnetic induction heating device is used to heat the fire surface at the bottom of the cylinder head nose bridge area simulation piece; the thermocouple is used to collect temperature data of the target observation point The fan is used to control the cooling rate of the cylinder head nose bridge area simulation part by adjusting the wind speed; the mechanical load applying device is used to apply a mechanical load to the cylinder head nose bridge area simulation part; the mechanical load includes: gas explosion pressure and the pre-tightening force of the bolt; the stress and strain sensor is used to collect stress data and strain response data of the cylinder head nose bridge area simulation part under the mechanical load; the displacement sensor is used to collect deformation data of the cylinder head nose bridge area simulation part under the mechanical load; the control unit is used to adaptively regulate the operating status of the mechanical load applying device and the electromagnetic induction heating device;

[0034] Step 200: Collecting whole-machine test data of the cylinder head nose bridge area simulation component under four load conditions based on the thermal-mechanical coupling fatigue test bench; the whole-machine test data includes: maximum temperature, minimum temperature, maximum burst pressure, and the burst time of the maximum burst pressure; the four load conditions include: 25% load rate, 50% load rate, 75% load rate, and 100% load rate;

[0035] Step 300: determining the preload force according to the maximum burst pressure;

[0036] Step 400: constructing a temperature load cycle curve according to the maximum temperature and the minimum temperature;

[0037] Step 500: constructing a mechanical load cycle curve according to the preload force and the burst moment;

[0038] Step 600: Using a preset mapping formula to fuse the temperature load cycle curve and the mechanical load cycle curve to obtain a temperature-mechanical cycle curve;

[0039] Step 700: Using the mechanical load applying device, perform a thermal-mechanical coupling fatigue test on the cylinder head nose bridge region simulation component to obtain stress-strain data; the stress-strain data includes: a maximum stress value and an average stress value;

[0040] Step 800: Determine 100 cycles of the thermal-mechanical coupling fatigue test as one coupling cycle;

[0041] Step 900: After each coupling cycle ends, collecting crack data of the cylinder head nose bridge area simulation component;

[0042] Step 1000: When the crack data reaches a preset failure boundary, stopping the thermal-mechanical coupling fatigue test and recording the thermal-mechanical coupling fatigue life;

[0043] Step 1100: Integrate the temperature-mechanical cycle curve, the crack data, and the thermal-mechanical coupling fatigue life to obtain test results.

[0044] Preferably, the failure margin is 5 mm.

[0045] Preferably, the calculation formula of the preload force is: P0 = (1.25-2)πR 2 P max ; Wherein, P0 is the preload force; P max is the maximum burst pressure; R is the average radius of the sealing zone.

[0046] Preferably, the mapping formula is: Δt1=n×Δt2; wherein Δt1 is the temperature cycle duration of the temperature load cycle curve; Δt2 is the mechanical cycle duration; and n is the cycle proportional coefficient.

[0047] Preferably, the cooling method of the thermal-mechanical coupling fatigue test bench is forced convection cooling.

[0048] refer to Figure 3A thermo-mechanical coupled fatigue test bench suitable for a cylinder head nose bridge simulated component was constructed. The test apparatus includes a fixture for firmly holding the test component, a mechanical load application device, an electromagnetic induction heating device, and a control unit. The test component is firmly clamped by bolts and a plate, limiting its freedom of movement during the test. The coolant flow path begins in the cylinder block water jacket, then enters the cooling water chamber inside the cylinder head, cooling the cylinder head, and ultimately discharges to the water tank through the cylinder head's water outlet manifold. The cooling water chamber within the cylinder head has a complex structure, typically composed of multiple irregular curved surfaces. This paper, based on the actual water chamber structure in the cylinder head nose bridge area, abstracts and simplifies a simulated cooling water channel structure with a T-shaped cross-section. Using electromagnetic induction heating technology, a specially designed coil precisely heats the bottom firing surface of the simulated component. Thermocouples are placed at key observation points to measure temperature changes in the cylinder head nose bridge area. To realistically simulate the environmental changes in the cylinder head, air is blown through the water channel during the cooling phase to achieve rapid cooling, and the cooling rate is controlled by adjusting the air speed. The mechanical load application device can simulate the various mechanical loads that the cylinder head is subjected to in actual operation, including bolt preload and gas explosion pressure. The bolt preload is simulated by the actual assembly torque, the size of which is precisely controlled by a torque wrench, and the gas explosion pressure is applied to the bottom of the simulation part through a hydraulic loading system. In addition to thermocouples, stress and strain sensors and displacement sensors are also installed to monitor the stress, strain response and deformation of the simulation part in the nose bridge area under load. Finally, the control unit automatically adjusts the operating status of the mechanical and temperature load application devices by receiving feedback signals from the sensors to ensure that the test is carried out according to the predetermined procedures.

[0049] Specifically, Figure 3 The schematic diagram of the structure of the flow channel in the water cavity of the actual nose bridge area of ​​the intake and exhaust valves is shown (the light gray area is the characteristic position nose bridge area). Starting from this flow channel, the present invention abstracts a simplified nose bridge area structure with a T-shaped water cavity cross-section. By extracting the structural dimension parameters of the characteristic position and corresponding them with the dimension parameters of the subsequent equivalent simulation parts, a clear dimensional relationship is established. The specific corresponding relationship is as follows: the distance between the intake and exhaust channels is W1, which corresponds to the total width of the equivalent simulation part; the distance between the intake and exhaust valve seats is W2, which corresponds to the width of the lower half of the T-shaped equivalent simulation part; the thickness of the cylinder head is H1, which corresponds to the total height of the equivalent simulation part; the length of the intake and exhaust channels is H2, which corresponds to the height of the upper half of the T-shaped equivalent simulation part; assuming that the distance between the cooling water channel and the intake and exhaust channels, the intake and exhaust valve seats, the top surface of the cylinder head and the bottom surface of the cylinder head are the same, they are uniformly corresponded to the thickness T of the equivalent simulation part; the total length L of the equivalent simulation part is consistent with the diameter of the intake and exhaust valve seats.

[0050] Specifically, the cooling water channel inlet temperature has a significant impact on cylinder head cooling. If the inlet temperature is too low, the cylinder head will experience increased heat dissipation losses, or even overcooling, leading to a decrease in engine power. If the inlet temperature is too high, the coolant may not be able to adequately cool the cylinder head, causing it to overheat. According to relevant literature, for optimal cooling, the inlet temperature of the engine cylinder head cooling water channel should be controlled between 60°C and 90°C.

[0051] Preferably, the correspondence between the temperature load cycle and the mechanical load cycle is explored:

[0052] 1) Temperature load cycle

[0053] refer to Figure 4 , a complete temperature cycle process is divided into the following three stages, and the duration of a temperature cycle is defined as Δt1:

[0054] Heating stage: The cylinder head is heated to the maximum temperature T max ,The length of this phase is determined by the power of the test bench;

[0055] Insulation stage: After reaching the maximum temperature, the cylinder head maintains this temperature for a period of time. This stage is achieved by controlling the fluctuation range of the measuring point temperature (for example, ±8°C);

[0056] Cooling stage: forced convection cooling is used until the temperature drops to the set minimum temperature T min Due to experimental condition limitations, the working fluid in the water channel structure was replaced by air, and the cooling rate was controlled by adjusting the wind speed in the air cooling system.

[0057] 2) Mechanical load cycle

[0058] refer to Figure 4 The hydraulic loading system applies a cyclically loaded sinusoidal hydraulic pressure curve to the bottom surface of the simulation component. This hydraulic pressure curve can well reproduce the gas pressure variation characteristics in the working cycle of the internal combustion engine. Specifically, the duration of a mechanical load cycle Δt2 is defined as the time interval between two adjacent peak burst pressure moments, where the peak value corresponds to the highest burst pressure P collected in the actual machine test. max , while the valley value is zero.

[0059] The bolt preload P0 is a constant value and is related to the maximum burst pressure P max This relationship can be expressed by the following formula:

[0060] P0=(1.25~2)πR 2 P max

[0061] Correspondence between temperature load cycle and mechanical load cycle:

[0062] A thermal-mechanical fatigue cycle consists of a temperature load cycle and n gas burst pressure cycles, accompanied by a constant bolt preload. The relationship between the cycle duration Δt1 and the mechanical cycle duration Δt2 is given by the following formula:

[0063] Δt1=n×Δt2

[0064] Where n is an integer and n ≥ 1. The value of n varies according to the specific operating conditions and generally exhibits a positive correlation with load and speed: that is, the greater the load and the higher the speed, the greater the value of n.

[0065] Furthermore, the thermal-mechanical coupling fatigue test was carried out according to the test process:

[0066] S1: The fire surface nose bridge area between the intake and exhaust valves of the cylinder head was selected as the key measurement area. Detailed test data of the entire engine was collected under four different load conditions: 25%, 50%, 75%, and 100%. This included the maximum explosion pressure of the cylinder head and the time of its occurrence, as well as the maximum and minimum temperatures.

[0067] S2: Calculate the corresponding bolt preload force based on the collected maximum burst pressure value.

[0068] S3: Combining the collected temperature and pressure data, we precisely determine the temperature cycle and burst pressure cycle curves, as well as the temperature-mechanical cycle curve. Under different load conditions, the amplitude, cycle duration, and n-value of the temperature-mechanical cycle curve show significant differences. These parameters must be precisely matched to actual operating conditions. The amplitude reflects the extreme temperature and pressure changes experienced by the cylinder head under a specific load, while the cycle duration corresponds to the time required to complete a complete thermal-mechanical cycle. The n-value represents the number of mechanical cycles included in a temperature cycle. This proportionality factor is directly related to the load level and speed, increasing with higher loads and faster speeds.

[0069] S4: Conduct thermal-mechanical coupled fatigue testing, paying particular attention to the maximum stress (Y1) and average stress (Y2) values ​​of the cylinder head nose bridge simulated component. The maximum stress (Y1) reveals the extreme stress state that may be reached in the stress concentration area, while the average stress (Y2) is obtained by integrating the stress values ​​at each moment in the test and dividing them by the unit cycle time, reflecting the overall stress state during the heating process.

[0070] S5: Observe the crack development of the simulated nose bridge component by stopping the machine every 100 cycles to inspect for cracks. The failure boundary is set at a crack length of 5 mm. At this point, the test is stopped and the thermal-mechanical coupled fatigue life (N) (number of cycles) is recorded.

[0071] Specifically, 25%, 50%, 75%, and 100% refer to the load rate, which is a percentage of the internal combustion engine's maximum effective power output at a constant speed. These ratios correspond to different operating conditions of the internal combustion engine. A 25% load rate represents the internal combustion engine operating at low load or idle, when the throttle opening is small, resulting in a limited amount of mixture entering the cylinder. A 50% load rate simulates the internal combustion engine operating state at medium load, which is a common operating condition in internal combustion engines in daily operation. 75% and 100% represent high load and full load conditions, respectively, when the throttle is nearly or fully open to allow more mixture to enter the cylinder. The whole-engine data collection test follows the following procedure: Start the internal combustion engine and gradually increase the rpm to its rated value to ensure stable operation. After applying a slight load and reaching a stable thermal state, the test begins. The load is gradually increased to various operating conditions, such as 25%, 50%, 75%, and 100% of rated power. Each time the load is adjusted, the throttle position is adjusted accordingly to maintain a constant rpm. Under each operating condition, key parameters are measured two or three times, including the maximum burst pressure and its occurrence time in the cylinder head, as well as the maximum and minimum temperatures in the nose bridge area. As the load increases, the injection volume per cycle increases, resulting in a greater amount of fuel in the combustible mixture formed in the same amount of time. This significantly increases the maximum burst pressure, and the time of peak burst pressure remains relatively constant. Furthermore, the maximum temperature occurs at the rated power point and increases with increasing load, showing a nearly linear relationship.

[0072] The beneficial effects of the present invention are as follows:

[0073] The present invention shortens the heating time and accelerates the test process by constructing a thermal-mechanical coupling fatigue test bench; by integrating temperature load cycle curves and mechanical load cycle curves, it realizes the simulation of the thermal-mechanical coupling effect of the cylinder head under actual working conditions; through four different load conditions, it provides more comprehensive analysis and data support; by designing a cylinder head nose bridge area simulation part with cooling water channels, it more accurately simulates the actual working state of the cylinder head, thereby improving the accuracy and representativeness of the test results.

[0074] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0075] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for thermal-mechanical coupling testing of a cylinder head simulation component, characterized in that: include: A thermal-mechanical coupling fatigue test bench was built based on the cylinder head nose bridge area simulation part; The thermal-mechanical coupling fatigue test bench includes: a fixture, a mechanical load applying device, an electromagnetic induction heating device, a thermocouple, a fan, a stress and strain sensor, a displacement sensor and a control unit; the fixture is used to fix the cylinder head nose bridge area simulation part through bolts and a plate; the cylinder head nose bridge area simulation part is T-shaped; the interior of the cylinder head nose bridge area simulation part is a hollow cooling water channel; the electromagnetic induction heating device is used to heat the fire surface at the bottom of the cylinder head nose bridge area simulation part; the thermocouple is used to collect temperature data of the target observation point; the fan is used to control the temperature by adjusting the wind speed. The cooling rate of the cylinder head nose bridge area simulation part is controlled; the mechanical load applying device is used to apply a mechanical load to the cylinder head nose bridge area simulation part; the mechanical load includes: gas explosion pressure and the pre-tightening force of the bolt; the stress and strain sensor is used to collect stress data and strain response data of the cylinder head nose bridge area simulation part under the mechanical load; the displacement sensor is used to collect deformation data of the cylinder head nose bridge area simulation part under the mechanical load; the control unit is used to adaptively control the operating status of the mechanical load applying device and the electromagnetic induction heating device; Collecting whole-machine test data of the cylinder head nose bridge area simulation component under four load conditions based on the thermal-mechanical coupling fatigue test bench; the whole-machine test data includes: maximum temperature, minimum temperature, maximum burst pressure, and the burst time of the maximum burst pressure; the four load conditions include: 25% load rate, 50% load rate, 75% load rate, and 100% load rate; determining the preload force according to the maximum burst pressure; constructing a temperature load cycle curve according to the maximum temperature and the minimum temperature; constructing a mechanical load cycle curve according to the preload force and the burst moment; The temperature load cycle curve and the mechanical load cycle curve are combined using a preset mapping formula to obtain a temperature-mechanical cycle curve; Using the mechanical load applying device, a thermal-mechanical coupling fatigue test is performed on the cylinder head nose bridge area simulation part to obtain stress-strain data; the stress-strain data includes: a maximum stress value and an average stress value; 100 cycles of the thermal-mechanical coupling fatigue test are determined as one coupling cycle; After each coupling cycle, collecting crack data of the cylinder head nose bridge area simulation part; When the crack data reaches a preset failure boundary, stopping the thermal-mechanical coupling fatigue test and recording the thermal-mechanical coupling fatigue life; The temperature-mechanical cycle curve, the crack data, and the thermal-mechanical coupling fatigue life are integrated to obtain test results.

2. A cylinder head simulation component thermal-mechanical coupling test method according to claim 1, characterized in that: The failure margin is 5 mm.

3. The method for thermal-mechanical coupling testing of a cylinder head simulation component according to claim 1, characterized in that: The calculation formula of the preload force is: P0 = (1.25 ~ 2) πR 2 P max ; Wherein, P0 is the preload force; P max is the maximum burst pressure; R is the average radius of the sealing zone.

4. The method for thermal-mechanical coupling testing of a cylinder head simulation component according to claim 1, characterized in that: The mapping formula is: Δt1=n×Δt2; wherein Δt1 is the temperature cycle duration of the temperature load cycle curve; Δt2 is the mechanical cycle duration; and n is the cycle proportional coefficient.

5. The method for thermal-mechanical coupling testing of a cylinder head simulation component according to claim 1, characterized in that: The cooling method of the thermal-mechanical coupling fatigue test bench is forced convection cooling.

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