Cylinder cover simulation part heat engine coupling test method

Abstract

The invention belongs to the technical field of cylinder cover heat engine coupling tests, and provides a cylinder cover simulation part heat engine coupling test method. Comprising the steps of building a heat engine coupling fatigue test bed, collecting complete machine test data, determining pre-tightening force, constructing a temperature load cycle curve, constructing a mechanical load cycle curve, fusing the curves, acquiring stress-strain data, determining a coupling period, collecting crack data, recording heat engine coupling fatigue life and integrating the data. According to the invention, by constructing the heat engine coupling fatigue test bench, the heating time is shortened, and the test progress is accelerated; through fusion of a temperature load circulation curve and a mechanical load circulation curve, heat engine coupling effect simulation of the cylinder cover in an actual working environment is realized; more comprehensive analysis and data support are provided through four different load working conditions; by designing the cylinder cover nose bridge area simulation piece with the cooling water channel, the actual working state of the cylinder cover is simulated more accurately, and the accuracy and representativeness of a test result are improved.

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 important structural components of the internal combustion engine. It is used to close the upper part of the cylinder and form a combustion chamber together with the top of the piston and the cylinder wall. The cylinder head has an extremely complex structure, on which are processed the intake and exhaust valves, valve guide holes, etc., and the cooling water channel, intake and exhaust pipes and part of the combustion chamber are cast inside. When the internal combustion engine is working, the working environment of the cylinder head is very harsh and the stress conditions are very complicated. It not only needs to bear the mechanical loads such as the bolt preload generated during the assembly process of the internal combustion engine, but also needs to bear the heat load generated by gas combustion and the gas explosion pressure load. At the same time, due to the existence of cooling water channels, factors such as the uneven distribution of the coolant flow path will also lead to complex distribution of temperature and stress fields inside the cylinder head.

[0003] During service, the cylinder head faces complex coupling effects of multiple physical fields, including thermal, fluid and solid coupling problems. However, traditional testing methods have some inherent limitations in dealing with these challenges, including high economic costs, lengthy test cycles, complex operating procedures, and limitations in accuracy and precision. Patent CN106610355A discloses a thermal engine fatigue test method and test equipment. This invention provides a thermal engine fatigue test method, which includes the following steps: setting load loading parameters; controlling the surface temperature of the sample to cycle within a set temperature range and applying a temperature load to the sample; applying a mechanical load to the sample according to a set functional relationship between the mechanical load and the temperature; and ending the test when the set number of cyclic loading is reached. This method can simultaneously control the loading mode of the temperature load and the mechanical load, realize the corresponding relationship between the two, and thus more accurately simulate the fatigue damage of the sample material under the combined action of mechanical load and thermal load. The test method is complete, has a short test cycle, high precision and good controllability, but lacks targeted design for specific parts of the nose bridge area of ​​the cylinder head, especially considering the complexity of the mechanical load in this area, including the influence of multiple loads such as bolt preload and gas explosion pressure. In addition, this technology only stays at the correlation of numerical values ​​in 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 prior art, the purpose of the present invention is to provide a thermal-mechanical coupling test method for a cylinder head simulation part, which shortens the heating time and speeds up the test process by constructing a thermal-mechanical coupling fatigue test bench; realizes the simulation of the thermal-mechanical coupling effect of the cylinder head in an actual working environment by integrating the temperature load cycle curve and the mechanical load cycle curve; and provides more comprehensive analysis and data support through four different load conditions.

[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 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-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 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 state of the mechanical load applying device and the electromagnetic induction heating device;

[0008] Based on the thermal-mechanical coupling fatigue test bench, whole-machine test data of the cylinder head nose bridge area simulation part under four load conditions are collected; the whole-machine test data include: maximum temperature, minimum temperature, maximum explosion pressure and the explosion time of the maximum explosion 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 fused by using a preset mapping formula to obtain a temperature-mechanical cycle curve;

[0013] Using the mechanical load applying device to carry out a thermal-mechanical coupling fatigue test 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] Determine 100 cycles of the thermal-mechanical coupling fatigue test as one coupling cycle;

[0015] After each coupling cycle ends, collecting crack data of the simulated component in the nose bridge area of ​​the cylinder head;

[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 explosion 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 proportionality 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 simulation of thermal-mechanical coupling effect of the cylinder head in an actual working environment is realized; by adopting a cylinder head nose bridge area simulation component with a cooling water channel, the defect of ignoring the water channel structure in conventional equivalent simulation components is solved, and a coupling test that is more in line with the actual situation 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 drawings required for use in the embodiments will be briefly introduced below. 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 creative labor.

[0025] Figure 1 A schematic diagram of a thermal-mechanical coupling test flow of a cylinder head simulation component provided by 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 A schematic diagram of a thermal-mechanical coupling test bench provided in an embodiment of the present invention;

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

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work 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 part, which shortens the heating time and speeds up the test process by constructing a thermal-mechanical coupling fatigue test bench; simulates the thermal-mechanical coupling effect of the cylinder head in an actual working environment by integrating the temperature load cycle curve and the mechanical load cycle curve; and provides more comprehensive analysis and data support through four different load conditions.

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

[0033] Step 100: A thermal-mechanical coupling fatigue test bench is constructed based on the cylinder head nose bridge area simulation piece; the thermal-mechanical coupling fatigue test bench comprises: a fixture, a mechanical load applying device, an electromagnetic induction heating device, a thermocouple, a fan, a stress-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 data; 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 strain sensor is used to collect the 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 the 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 state of the mechanical load applying device and the electromagnetic induction heating device;

[0034] Step 200: Based on the thermal-mechanical coupling fatigue test bench, whole-machine test data of the cylinder head nose bridge area simulation part under four load conditions are collected; the whole-machine test data include: maximum temperature, minimum temperature, maximum explosion pressure and the explosion time of the maximum explosion 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 time;

[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 to carry out a thermal-mechanical coupling fatigue test 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;

[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 part;

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

[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 explosion 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 proportionality coefficient.

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

[0048] refer to Figure 3, a thermal-mechanical coupling fatigue test bench suitable for the simulated parts in the nose bridge area of ​​the cylinder head is built. The test device includes a fixture for firmly clamping the test piece, a mechanical load application device, an electromagnetic induction heating device and a control unit. The test piece is firmly clamped by bolts and a plate, which limits its freedom during the test. The flow path of the coolant starts from the cylinder water jacket, then enters the cooling water cavity inside the cylinder head to cool the cylinder head, and finally discharges to the water tank through the water outlet main of the cylinder head. The cooling water cavity in the cylinder head has a complex structure and is usually composed of multiple irregular curved surfaces. Starting from the real water cavity structure in the nose bridge area of ​​the cylinder head, the present invention abstracts and simplifies a simulated cooling water channel structure with a T-shaped cross-section. Using electromagnetic induction heating technology, a specially designed coil is used to accurately heat the bottom fire surface of the simulated part, and thermocouples are arranged at key observation points to measure the temperature changes in the nose bridge area of ​​the cylinder head. In order to truly simulate the environmental changes of the cylinder head, rapid cooling is achieved by blowing air into the water channel during the cooling stage, and the cooling rate is controlled by adjusting the wind speed. The mechanical load application device can simulate various mechanical loads that the cylinder head is subjected to in actual work, including bolt preload and gas explosion pressure. The bolt preload is simulated by the actual assembly torque, and the size is precisely controlled by the torque wrench. The gas explosion pressure is applied to the bottom of the simulation part through the hydraulic loading system. In addition to thermocouples, stress strain sensors and displacement sensors are also installed to monitor the stress, strain response and deformation of the simulation parts 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 the feedback signal from the sensor to ensure that the test is carried out according to the predetermined procedure.

[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 the 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 to 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, corresponding to the total width of the equivalent simulation part; the distance between the intake and exhaust valve seats is W2, corresponding to the width of the lower half of the T-type equivalent simulation part; the thickness of the cylinder head is H1, corresponding to the total height of the equivalent simulation part; the length of the intake and exhaust channels is H2, corresponding to the height of the upper half of the T-type 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 is the same, it uniformly corresponds 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 inlet temperature of the cooling water channel has an important impact on the cooling of the cylinder head. If the inlet temperature is too low, the heat dissipation loss of the cylinder head will increase, or even be overcooled, resulting in a decrease in the power of the internal combustion engine; if the inlet temperature of the cooling water channel is too high, the coolant may not cool the cylinder head enough, causing the cylinder head to overheat. According to relevant literature, in order to achieve the best cooling effect, the inlet temperature of the engine cylinder head cooling water channel should be controlled between 60°C and 90°C.

[0051] Preferably, the corresponding relationship 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 highest 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 the limitation of test conditions, 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 on the bottom surface of the simulation part. 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 maximum 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 working conditions and usually shows a positive correlation with the 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 valve and the exhaust valve of the cylinder head was selected as the key measurement area, and detailed whole machine test data under four different load conditions of 25%, 50%, 75% and 100% were collected, including the maximum explosion pressure of the cylinder head and its occurrence time, 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, the temperature cycle and burst pressure cycle curves are accurately determined, and the temperature-mechanical cycle curve is determined. Under different load conditions, the amplitude, single cycle duration and n value of the temperature-mechanical cycle curve show obvious differences. These parameters must accurately match the actual operating conditions. The amplitude reflects the extreme values ​​of the temperature and pressure changes experienced by the cylinder head under a specific load, while the single cycle duration corresponds to the time required to complete a complete heat-mechanical cycle. The n value represents the number of mechanical cycles contained in a temperature cycle. This proportionality coefficient is directly related to the load level and speed. The higher the load and the faster the speed, the larger the value.

[0069] S4: Conduct thermal-mechanical coupling fatigue tests, and pay special attention to the maximum stress value Y1 and average stress value Y2 of the cylinder head nose bridge area simulation part. The maximum stress value Y1 reveals the extreme stress state that may be reached in the stress concentration area, while the average stress value Y2 is obtained by time-integrating the stress values ​​at each moment during the test and dividing them by the unit cycle time, reflecting the overall stress state during the heating process.

[0070] S5: The crack development of the simulated part in the bridge of nose area was observed by stopping the machine for crack inspection every 100 cycles. The failure boundary was set to the crack length reaching 5 mm, at which point the test was stopped and the thermal-mechanical coupling fatigue life N (number of cycles) was recorded.

[0071] Specifically, 25%, 50%, 75% and 100% refer to the load rate, which is a measure of the 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. The 25% load rate represents the operation of the internal combustion engine at a small load or idle state, when the throttle opening is small, resulting in a limited amount of mixed gas entering the cylinder. The 50% load rate simulates the working state of the internal combustion engine at a medium load, which is a common operating condition of the internal combustion engine in daily operation. 75% and 100% represent high load and full load conditions, respectively, when the throttle is close to or fully open to allow more mixed gas to enter the cylinder. In the whole machine data collection test, the operation process is as follows: start the internal combustion engine and gradually increase the speed to its calibrated value to ensure stable operation; add a little load to reach a stable thermal state before starting the test, and gradually increase the load according to different working conditions such as 25%, 50%, 75%, and 100% of the rated power. Each time the load is adjusted, the throttle position should be adjusted accordingly to keep the speed unchanged; under each working condition, measure 2 to 3 key parameters, including the maximum explosion pressure of the cylinder head and its occurrence time, as well as the highest and lowest temperatures in the nose bridge area. As the load increases, the amount of fuel injected per cycle increases, which leads to an increase in the amount of fuel in the combustible mixture formed in the same time, thereby significantly increasing the maximum explosion pressure, and the time of occurrence of the maximum explosion pressure is relatively fixed. In addition, the highest temperature appears at the rated power point and increases with the increase of load, showing an approximately linear relationship.

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

[0073] The present invention shortens the heating time and speeds up the test process by constructing a thermal-mechanical coupling fatigue test bench; realizes the simulation of the thermal-mechanical coupling effect of the cylinder head under the actual working environment by integrating the temperature load cycle curve and the mechanical load cycle curve; provides more comprehensive analysis and data support through four different load conditions; and more accurately simulates the actual working state of the cylinder head by designing a cylinder head nose bridge area simulation part with a cooling water channel, 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] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for thermal-mechanical coupling test 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 comprises: a fixture, a mechanical load applying device, an electromagnetic induction heating device, a thermocouple, a fan, a stress-strain sensor, a displacement sensor and a control unit; the fixture is used to fix the cylinder head nose bridge area simulation part by 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 adjust the wind speed control 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-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 state of the mechanical load applying device and the electromagnetic induction heating device; Based on the thermal-mechanical coupling fatigue test bench, whole-machine test data of the cylinder head nose bridge area simulation part under four load conditions are collected; the whole-machine test data include: maximum temperature, minimum temperature, maximum explosion pressure and the explosion time of the maximum explosion 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 fused by using a preset mapping formula to obtain a temperature-mechanical cycle curve; Using the mechanical load applying device to carry out a thermal-mechanical coupling fatigue test 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; Determine 100 cycles of the thermal-mechanical coupling fatigue test as one coupling cycle; After each coupling cycle ends, collecting crack data of the simulated component in the nose bridge area of ​​the cylinder head; 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. A cylinder head simulation component thermal-mechanical coupling test method 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 explosion pressure; R is the average radius of the sealing zone.

4. A cylinder head simulation component thermal-mechanical coupling test method 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 proportionality coefficient.

5. The method for thermal-mechanical coupling test 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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