A fatigue life analysis method, correction method and storage medium for engineering machinery crawler chassis

Abstract

The present invention discloses a fatigue life analysis method, correction method and storage medium for a crawler chassis of an engineering machinery, comprising: obtaining a multi-body dynamics model to determine a simulation working condition; performing simulation of different working conditions through the corrected dynamics model, obtaining stress curves of the surface nodes of crawler chassis parts under different working conditions as load spectrum samples; performing statistical processing on the load spectrum samples, calculating fatigue damage values ​​of crawler chassis parts under different working conditions and nodes, and obtaining fatigue damage values ​​of different nodes on the surface of crawler chassis parts under different working conditions; constructing an overall load spectrum, weightedly calculating fatigue damage values ​​of different nodes on the surface of crawler chassis parts under different working conditions, obtaining weighted values ​​of fatigue damage at different working conditions and nodes, and calculating the overall fatigue life of the crawler chassis based on the values. Corresponding correction measures are also determined by comparing the design life, the overall fatigue life of the crawler chassis and the actual service life of the crawler chassis. The method proposed by the present invention takes into account a variety of working conditions and has higher accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to an analysis method, a correction method and a storage medium for fatigue life of an engineering machinery crawler chassis. Background Art

[0002] Crawler engineering machinery is widely used in the construction of mines, roads and bridges, and the crawler chassis bears the weight of the whole machine and transmits the working load. The working conditions are harsh and the loads are complex and changeable. The crawler chassis of engineering machinery includes crawlers, supporting rollers, guide wheels, sprocket wheels, drive wheels and frames. Especially in mining conditions, where there is dense gravel, large vibration and impact, and long-term continuous heavy-load work, the various parts of the crawler chassis of engineering machinery are subjected to alternating loads for a long time, and fatigue failure is prone to occur. The micro-cracks that arise will cause cracks after expansion, or even sudden breakage, which seriously threatens personnel and production safety.

[0003] At present, the stress ratio method is often used to evaluate the fatigue life of engineering machinery crawler chassis during design. The safety factor is calculated by calculating the maximum stress under extreme working conditions and comparing it with the allowable fatigue strength. There are also methods that input the measured load spectrum into the finite element model and evaluate the fatigue life in combination with the material SN curve. However, the stress ratio method only considers extreme working conditions, and the fatigue life results are conservative. The various components of the engineering machinery crawler chassis are constantly running and squeezing each other during operation. It is difficult to stick strain gauges and other collection devices in high stress areas, making it difficult to collect stress load spectra, and it is impossible to input the measured load spectrum into the finite element model to evaluate the fatigue life. Summary of the invention

[0004] The purpose of the present invention is to provide a fatigue life analysis method, correction method and storage medium for a crawler chassis of an engineering machinery, which adopts a multi-body dynamics model simulation, and weightedly calculates the fatigue damage value of each working condition according to the surface nodes of the flexible body of the parts, so as to calculate the fatigue life of the crawler chassis of the engineering machinery, and covers a wide range of working conditions, and is accurate and efficient. The present invention is achieved through the following technical solutions.

[0005] The present invention provides a method for analyzing fatigue life of a crawler chassis of an engineering machinery, comprising:

[0006] Access pre-built multibody dynamics models;

[0007] The rigid body of the crawler chassis components is replaced by a flexible body, and the elastic modulus, Poisson's ratio and density of the flexible body components are input into the multi-body dynamics model to perform simulation of different working conditions;

[0008] Obtain stress curves of the surface nodes of the flexible body parts of the crawler chassis under different working conditions, and use the stress curves as load spectrum samples;

[0009] The load spectrum samples are statistically processed by using the rain flow counting method to calculate the fatigue damage values ​​of the flexible body parts of the crawler chassis under different working conditions and nodes, and the fatigue damage values ​​of different nodes on the surface of the flexible body parts of the crawler chassis under different working conditions are obtained;

[0010] According to the design life, the proportion of each working condition time and the load spectrum sample length, the load spectrum samples of each working condition are extended and combined to construct the overall load spectrum, and the fatigue damage values ​​of different nodes on the surface of the flexible body parts of the crawler chassis under the said working conditions are weighted to obtain the weighted values ​​of fatigue damage of each node under each working condition; the overall fatigue life of the crawler chassis is calculated based on the weighted values ​​of fatigue damage of each node under each working condition .

[0011] In practical applications, since the stress ratio method is used to evaluate the fatigue life of the crawler chassis, only the extreme working conditions are considered, and the fatigue life result finally calculated is conservative. The present invention comprehensively considers multiple working conditions, investigates the actual working conditions and time proportion of the crawler chassis, and uses multi-body dynamics model simulation to obtain the stress load spectrum of each sub-condition, and extends the combination according to the working condition time proportion to construct the overall load spectrum of the crawler chassis. The fatigue damage of the sub-condition is weightedly calculated according to the surface nodes of the flexible body of the parts to obtain the overall fatigue life of the engineering machinery crawler chassis, and the fatigue influence coefficient is corrected according to the first fatigue cracking fault location and fault time.

[0012] The overall load spectrum of the engineering machinery crawler chassis constructed by the present invention is consistent with the design life of the crawler chassis, indicating that the simulation duration is consistent with the actual duration, which increases the accuracy of the simulation experiment results. The present invention does not require actual measurement to collect the load spectrum, effectively saving the test cost, and overcoming the problem that the various components of the crawler chassis are constantly running and squeezing each other during the working process, and it is difficult to stick strain gauges and other collection devices in high stress areas, making it difficult to collect stress load spectra.

[0013] Optionally, the load spectrum samples are statistically processed by the rain flow counting method to calculate the fatigue damage values ​​of the flexible body parts of the crawler chassis under different working conditions and nodes, including calculating the fatigue damage values ​​of the flexible body parts of the crawler chassis under different working conditions in combination with the SN curve considering the weighted coefficient of fatigue influence,

[0014] The SN curve needs to be based on the material SN curve, take into account the fatigue influence coefficient, and calculate the fatigue influence weighted coefficient to reflect the influence of the size and surface processing conditions of the parts on the fatigue life.

[0015] The fatigue influence weighting factor Calculated by the following formula:

[0016] ,

[0017] In the formula, is the stress concentration factor, is the surface coefficient, is the size factor, is the load factor, For other coefficients.

[0018] Optionally, the fatigue damage value calculation of the flexible body parts of the crawler chassis under different working conditions and nodes includes calculating the extension multiple of the load spectrum sample under different working conditions, and then using the extension multiple of the load spectrum sample under different working conditions, the fatigue damage value of the load spectrum sample under different nodes and working conditions, and the design life of the crawler chassis. , the sample duration of the load spectrum and the proportion of each working condition are used to calculate the fatigue damage values ​​of different nodes on the surface of the crawler chassis components under different working conditions.

[0019] The load sample spectrum extension multiples for each working condition are calculated by the following formula:

[0020] ,

[0021] In the formula, Indicates the serial number of the sub-conditions. The value range is , is the total number of working conditions, For working conditions The load spectrum sample extension multiple, For working conditions The sample duration of the load spectrum under For working conditions The proportion of time in all working conditions;

[0022] Any node on the surface of the crawler chassis components under different working conditions The fatigue damage value is calculated by the following formula:

[0023] ,

[0024] In the formula, For working conditions Surface nodes of lower track chassis components The fatigue damage value of For working conditions node Load spectrum sample fatigue damage value, is the node number, The value range is , is the total number of nodes; The load spectrum sample is the working condition part of the duration.

[0025] Optionally, the weighted value of fatigue damage of each node under each working condition is calculated by the following formula:

[0026] ,

[0027] In the formula, It is the weighted value of fatigue damage of each node in each working condition.

[0028] Optionally, the calculation of the overall fatigue life of the crawler chassis , including calculating the fatigue life of the crawler chassis at each node, taking the minimum value of the fatigue life of the crawler chassis at each node as the overall fatigue life of the crawler chassis ;

[0029] The fatigue life of the crawler chassis at each node is calculated by the following formula:

[0030] ,

[0031] In the formula, For each node Fatigue life of track chassis;

[0032] The overall fatigue life of the crawler chassis Calculated by the following formula:

[0033] .

[0034] Optionally, the working condition simulation includes determining working condition influencing factors according to the working condition, combining multiple factors according to the driving speed, road surface, and posture, and simulating the actual working condition to perform working condition simulation;

[0035] The obtaining of the multi-body dynamics model includes modifying the multi-body dynamics model. The modified multi-body dynamics model includes analyzing according to the determined simulation working conditions, extracting the track tension, driving wheel torque, and supporting wheel force, and modifying the mass distribution, moment of inertia, motion drive, and friction coefficient of the multi-body dynamics model by comparing with the actual measured forces in the test, so that the multi-body dynamics model of the whole machine is consistent with the actual measurement.

[0036] The multi-body dynamics simulation model at least includes a crawler assembly formed by connecting single crawler sections, which can realize the actions of vehicle rotation, vehicle driving and excavation.

[0037] In a second aspect, the present invention provides a method for correcting a crawler chassis of an engineering machinery, characterized in that the method for analyzing fatigue life of a crawler chassis of an engineering machinery described in the first aspect is adopted, comprising:

[0038] Design life , Overall fatigue life of track chassis and the actual service life of the crawler chassis Compare and determine the corresponding correction measures. , indicating that the overall fatigue life of the track chassis of the design scheme is Failure to achieve the required design life , measures must be taken to strengthen and optimize the design: improve the structure of each component of the crawler chassis, reduce the stress in dangerous parts of the components; select materials with strong fatigue resistance, use surface cold working hardening or surface heat treatment strengthening to produce residual compressive stress on the surface of the parts.

[0039] Optionally, the design life , Overall fatigue life of track chassis and the actual service life of the crawler chassis The comparison of the above data will determine the corresponding corrective measures, including:

[0040] like , indicating that the overall fatigue life of the crawler chassis of the design scheme can reach the required design life, but the actual service life of the crawler chassis cannot reach the design life, and measures must be taken to optimize the process: control the processing technology according to the pre-designed surface roughness of each component of the crawler chassis, control the generation of harmful surface residual tensile stress during the manufacturing process of parts; prevent the blank material from having defects such as segregation, decarburization, inclusions, and cracks. At the same time, optimize the operating instruction manual, avoid and reduce the corrosion during operation when using the crawler chassis, avoid sudden load increases due to misoperation; conduct regular inspections to prevent fatigue and wear failure of crawler chassis products;

[0041] According to the complex and variable loads in actual use, correct the other coefficients shown , recalculate the overall fatigue life of the track chassis , so that the overall fatigue life of the track chassis is recalculated Equal to actual service life ,at this time , then improve the structure of parts and reduce the stress in dangerous parts of parts; select materials reasonably and adopt strengthening technology, choose materials with stronger fatigue resistance, use surface cold working hardening or surface heat treatment strengthening to generate residual compressive stress on the surface of parts.

[0042] In a third aspect, the present invention provides a storage medium, comprising:

[0043] Memory, for storing computer programs / instructions;

[0044] A processor is used to execute the computer program / instructions to implement the steps of the engineering machinery crawler chassis fatigue life analysis method described in the first aspect or the steps of the engineering machinery crawler chassis correction method described in the second aspect.

[0045] Beneficial Effects

[0046] The present invention does not require actual measurement and collection of load spectra, which effectively saves test costs; the present invention comprehensively considers multiple working conditions, covers a wide range of working conditions, overcomes the deficiency of the stress ratio method that only analyzes extreme working conditions, and improves the accuracy of fatigue life assessment of engineering machinery crawler chassis. In addition, the method of the present invention can also be used to perform multiple rounds of iterations on the design of engineering machinery crawler chassis parts to evaluate and compare the fatigue life of each solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the process of fatigue life analysis method of engineering machinery crawler chassis in one embodiment of the present invention;

[0049] Figure 2 Shown is a schematic diagram of the operating condition factors of the present invention;

[0050] Figure 3 Shown is a schematic diagram of the multi-body dynamics model of the present invention;

[0051] Figure 4 The figure shows the schematic diagram of the driving wheel torque of the multi-body dynamics model of the present invention;

[0052] Figure 5 The figure shows the force diagram of a single track section of the multi-body dynamics model of the present invention;

[0053] Figure 6 The figure shows the force diagram of the track wheel of the multi-body dynamics model of the present invention;

[0054] Figure 7 Shown is a schematic diagram of the node stress on the surface of the track link under the uphill working condition of the multi-body dynamic model of the present invention. DETAILED DESCRIPTION

[0055] The following is a further description in conjunction with the accompanying drawings and specific embodiments. In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0056] Example 1

[0057] This embodiment introduces a fatigue life analysis method for a crawler chassis of an engineering machinery, including:

[0058] Access pre-built multibody dynamics models;

[0059] The rigid body of the crawler chassis components is replaced by a flexible body, and the elastic modulus, Poisson's ratio and density of the flexible body components are input into the multi-body dynamics model to perform simulation of different working conditions;

[0060] Obtain stress curves of the surface nodes of the flexible body parts of the crawler chassis under different working conditions, and use the stress curves as load spectrum samples;

[0061] The load spectrum samples are statistically processed by using the rain flow counting method to calculate the fatigue damage values ​​of the flexible body parts of the crawler chassis under different working conditions and nodes, and the fatigue damage values ​​of different nodes on the surface of the flexible body parts of the crawler chassis under different working conditions are obtained;

[0062] According to the design life, the proportion of each working condition time and the load spectrum sample length, the load spectrum samples of each working condition are extended and combined to construct the overall load spectrum, and the fatigue damage values ​​of different nodes on the surface of the flexible body parts of the crawler chassis under the said working conditions are weighted to obtain the weighted values ​​of fatigue damage of each node under each working condition; the overall fatigue life of the crawler chassis is calculated based on the weighted values ​​of fatigue damage of each node under each working condition .

[0063] In practical applications, since the stress ratio method is used to evaluate the fatigue life of the crawler chassis, only the extreme working conditions are considered, and the fatigue life result finally calculated is conservative. The present invention comprehensively considers multiple working conditions, investigates the actual working conditions and time proportion of the crawler chassis, and uses multi-body dynamics model simulation to obtain the stress load spectrum of each sub-condition, and extends the combination according to the working condition time proportion to construct the overall load spectrum of the crawler chassis. The fatigue damage of the sub-condition is weightedly calculated according to the surface nodes of the flexible body of the parts to obtain the overall fatigue life of the engineering machinery crawler chassis, and the fatigue influence coefficient is corrected according to the first fatigue cracking fault location and fault time.

[0064] The overall load spectrum of the engineering machinery crawler chassis constructed by the present invention is consistent with the design life of the crawler chassis, indicating that the simulation duration is consistent with the actual duration, which increases the accuracy of the simulation experiment results. The present invention does not require actual measurement to collect the load spectrum, effectively saving the test cost, and overcoming the problem that the various components of the crawler chassis are constantly running and squeezing each other during the working process, and it is difficult to stick strain gauges and other collection devices in high stress areas, making it difficult to collect stress load spectra.

[0065] Example 2

[0066] Based on Example 1, this example introduces a specific implementation process of a fatigue life analysis method for a crawler chassis of an engineering machinery, such as Figure 1 As shown, specifically including the following:

[0067] 1. Determine the simulation conditions

[0068] In this embodiment, through field surveys, user interview questionnaires, equipment work data analysis, etc., the operating conditions of the excavator host and hosts of the same tonnage throughout their life cycle are investigated, the actual operating conditions are determined, mathematical statistics are performed based on the actual survey data, and the operating conditions and the proportion of operating time are collected.

[0069] Determine the operating condition influencing factors according to the operating conditions, such as Figure 2 As shown, the working condition influencing factors include driving speed, road surface and posture. Then, multiple factors are combined according to the driving speed, road surface and posture to simulate the actual use working condition and determine the simulation working conditions: idling, low-speed forward on flat road, low-speed reverse on flat road, high-speed forward on flat road, high-speed reverse on flat road, slope driving, uphill working condition, downhill working condition, braking steering, in-situ steering, differential steering, forward farthest excavation, lateral farthest excavation, oblique farthest excavation, deepest excavation, granular bed road driving, earthwork bulk material excavation, stonework bulk material excavation and other working conditions. Since the working conditions encountered by the crawler chassis in actual operation are very complex, in other embodiments, multiple working conditions different from this embodiment can be simulated continuously. Figure 2 Other speeds include stationary, that is, idling, and other road surfaces include granular bed roads, such as cobblestone roads, swamps, and gravel roads that can simulate them.

[0070] 2. Constructing a multi-body dynamics model for simulation

[0071] Construct the whole machine multi-body dynamics model as Figure 3 As shown, according to the determined simulation working conditions, analysis is performed to extract the forces of other components such as track tension, drive wheel torque, supporting wheel force, etc. By comparing with the actual measured forces in the experiment, the mass distribution, moment of inertia, motion drive, friction coefficient, etc. of the multi-body dynamics model are corrected to make the multi-body dynamics model of the whole machine consistent with the actual measurement. Figure 4-Figure 6 They are the driving wheel torque of the crawler chassis, the force of a single crawler section, and the dynamic load curve of the supporting wheel, i.e., the force diagram. The force diagrams of other parts of the crawler chassis are similar to the above force diagrams. The multi-body dynamics simulation model in this embodiment at least includes a crawler assembly connected by a single crawler section, which can realize the actions of vehicle rotation, vehicle driving, and excavation.

[0072] When the constructed multi-body dynamics model is driving on a granular bed road or excavating bulk earth or stone, rigid-bulk coupling simulation is used. A 3D laser scanner is used to scan the shape of typical bulk materials, such as stones, to obtain the real bulk material shape. Experiments are used to calibrate the bulk material's stacking angle, density, restitution coefficient, shear modulus and other parameters.

[0073] Some working conditions may cause the whole machine to become unstable, such as when digging in the farthest direction and the bucket is extended to the farthest position on the horizontal ground. The digging may cause the whole machine to tilt backwards. The control system or hydraulic system should be combined for simulation to limit the cylinder pressure to not exceed the overflow pressure to prevent abnormal load.

[0074] 3. Calculation

[0075] Replace the rigid body model of track chassis components, such as the track link, with a meshed finite element flexible body, and replace the lower frame with a modal flexible body. Perform rigid-flexible coupling simulation for each working condition, and obtain the surface node stress curve of the flexible body components under each working condition as the load spectrum for fatigue durability performance calculation and life assessment. Figure 7 The figure shows the stress diagram of the node on the surface of the track link under the uphill working condition of the multi-body dynamics model. Stress is the stress generated inside the component after receiving the external force. Since fatigue failure often starts from the surface of the part, the higher the stress amplitude, the easier it is to fail. The stress amplitude is the difference between the maximum and minimum stress values ​​in one cycle. Figure 7 In the above, taking the uphill working condition as an example, six surface nodes of the flexible body parts of the track link that are prone to failure are extracted. Generally, a period of time, such as 18 seconds of stress curve between 2s and 20s, is intercepted as a load spectrum sample, but the load spectrum sample at least includes a complete typical working load, such as a full circle of stable operation of the crawler assembly.

[0076] The load spectrum samples are statistically processed using the rain flow counting method to calculate the fatigue damage values ​​of the flexible body parts of the track chassis under different working conditions and nodes, including the fatigue damage calculation of the flexible body parts of the track chassis under different working conditions in combination with the SN curve considering the weighted coefficient of fatigue influence.

[0077] The SN curve needs to be based on the material SN curve, take into account the fatigue influence coefficient, and calculate the fatigue influence weighted coefficient to reflect the influence of the size and surface processing conditions of the parts on the fatigue life.

[0078] The fatigue influence weighting factor Calculated by the following formula:

[0079] ,

[0080] In the formula, is the stress concentration factor, is the surface coefficient, is the size factor, is the load factor, For other coefficients.

[0081] 3.1 Calculate the extension multiple of the load spectrum sample for each working condition

[0082] Table 1 shows the load spectrum extension times of a track link of a flexible component in the crawler chassis of the engineering machinery in this embodiment under different working conditions. Table 1 is also applicable to other components.

[0083] The load spectrum sample extension multiples for each working condition are calculated by the following formula:

[0084] ,

[0085] In the formula, Indicates the serial number of the sub-conditions. The value range is , is the total number of working conditions, For working conditions The load spectrum sample extension multiple, For working conditions The sample duration of the load spectrum under For working conditions The proportion of time in all working conditions.

[0086] formula This indicates that the overall load spectrum of the engineering machinery crawler chassis constructed in this embodiment is consistent with the design life of the crawler chassis, indicating that the simulation duration is consistent with the actual duration, which increases the accuracy of the simulation experiment results.

[0087] Table 1 Load spectrum extension of engineering machinery crawler chassis in different working conditions

[0088] 3.2 Calculation of fatigue damage values ​​at different nodes on the surface of track chassis components under different working conditions

[0089] As shown in Table 2, the fatigue life of the overall crawler chassis of the engineering machinery in this embodiment is calculated. Table 2 contains the fatigue damage values ​​of the track link of one of the components of the crawler chassis of the engineering machinery under different working conditions and different nodes. The calculation of fatigue damage values ​​of other components of the crawler chassis of the engineering machinery under different working conditions and different nodes is similar to Table 2.

[0090] Calculate the fatigue damage value of different nodes on the surface of the crawler chassis parts under different working conditions, including using the load spectrum sample extension multiples of the different working conditions, the fatigue damage value of the load spectrum sample under different working conditions at different nodes, and the design life of the crawler chassis , the sample duration of the load spectrum and the proportion of each working condition are used to calculate the fatigue damage values ​​of different nodes on the surface of the crawler chassis components under different working conditions.

[0091] Any node on the surface of the crawler chassis components under different working conditions The fatigue damage value is calculated by the following formula:

[0092] ,

[0093] In the formula, For working conditions Surface nodes of lower track chassis components The fatigue damage value of For working conditions node Load spectrum sample fatigue damage value, is the node number, The value range is , is the total number of nodes; The load spectrum sample is the working condition part of the duration.

[0094] The weighted value of fatigue damage of each node under each working condition is calculated by the following formula:

[0095] ,

[0096] In the formula, It is the weighted value of fatigue damage of each node in each working condition.

[0097] Table 2 Calculation of overall fatigue life of engineering machinery crawler chassis components

[0098] 3.3 Calculation of overall fatigue life of track chassis

[0099] The fatigue life of the crawler chassis at each node is calculated by the following formula:

[0100] ,

[0101] In the formula, For each node Fatigue life of track chassis;

[0102] The overall fatigue life of the crawler chassis Calculated by the following formula:

[0103] .

[0104] Example 3

[0105] Based on Example 2, this example introduces a method for correcting a crawler chassis of an engineering machinery, including the following contents:

[0106] Design life , Overall fatigue life of track chassis and the actual service life of the crawler chassis Comparison of the results to determine the appropriate corrective measures:

[0107] like , indicating that the overall fatigue life of the track chassis of the design scheme is Failure to achieve the required design life , measures must be taken to strengthen and optimize the design: improve the structure of each component of the crawler chassis, reduce the stress in dangerous parts of the components; select materials with strong fatigue resistance, use surface cold working hardening or surface heat treatment strengthening to produce residual compressive stress on the surface of the parts.

[0108] like , indicating that the overall fatigue life of the crawler chassis of the design scheme can reach the required design life, but the actual service life of the crawler chassis cannot reach the design life, and measures must be taken to optimize the process: control the processing technology according to the pre-designed surface roughness of each component of the crawler chassis, control the generation of harmful surface residual tensile stress during the manufacturing process of parts; prevent the blank material from having defects such as segregation, decarburization, inclusions, and cracks. At the same time, optimize the operating instruction manual, avoid and reduce the corrosion during operation when using the crawler chassis, avoid sudden load increases due to misoperation; conduct regular inspections to prevent fatigue and wear failure of crawler chassis products;

[0109] According to the complex and variable loads in actual use, correct the other coefficients shown , recalculate the overall fatigue life of the track chassis , so that the overall fatigue life of the track chassis is recalculated Equal to actual service life ,at this time , then improve the structure of parts and reduce the stress in dangerous parts of parts; select materials reasonably and adopt strengthening technology, choose materials with stronger fatigue resistance, use surface cold working hardening or surface heat treatment strengthening to generate residual compressive stress on the surface of parts.

[0110] Example 3

[0111] This embodiment provides a storage medium, including:

[0112] Memory, for storing computer programs / instructions;

[0113] A processor is used to execute the computer program / instructions to implement the steps of the engineering machinery crawler chassis fatigue life analysis method described in Example 1 or the steps of the engineering machinery crawler chassis correction method described in Example 2.

[0114] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0115] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0116] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0117] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0118] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A fatigue life analysis method for a crawler chassis of an engineering machinery, characterized in that: include: Access pre-built multibody dynamics models; The rigid body of the crawler chassis components is replaced by a flexible body, and the elastic modulus, Poisson's ratio and density of the flexible body components are input into the multi-body dynamics model to perform simulation of different working conditions; Obtain stress curves of the surface nodes of the flexible body parts of the crawler chassis under different working conditions, and use the stress curves as load spectrum samples; The load spectrum samples are statistically processed by using the rain flow counting method to calculate the fatigue damage values ​​of the flexible body parts of the crawler chassis under different working conditions and nodes, and the fatigue damage values ​​of different nodes on the surface of the flexible body parts of the crawler chassis under different working conditions are obtained; According to the design life, the proportion of each working condition time and the load spectrum sample length, the load spectrum samples of each working condition are extended and combined to construct the overall load spectrum, and the fatigue damage values ​​of different nodes on the surface of the flexible body parts of the crawler chassis under the said working conditions are weighted to obtain the weighted values ​​of fatigue damage of each node under each working condition; the overall fatigue life of the crawler chassis is calculated based on the weighted values ​​of fatigue damage of each node under each working condition .

2. The fatigue life analysis method of engineering machinery crawler chassis according to claim 1 is characterized in that: The load spectrum samples are statistically processed by the rain flow counting method to calculate the fatigue damage values ​​of the flexible body parts of the crawler chassis under different working conditions and nodes, including the fatigue damage calculation of the flexible body parts of the crawler chassis under different working conditions in combination with the SN curve considering the weighted coefficient of fatigue influence, The fatigue influence weighting factor Calculated by the following formula: ， In the formula, is the stress concentration factor, is the surface coefficient, is the size factor, is the load factor, For other coefficients.

3. The fatigue life analysis method of engineering machinery crawler chassis according to claim 1 is characterized in that: The fatigue damage value calculation of the flexible body parts of the crawler chassis under different working conditions and nodes includes calculating the extension multiple of the load spectrum sample under different working conditions, and then using the extension multiple of the load spectrum sample under different working conditions, the fatigue damage value of the load spectrum sample under different nodes and working conditions, and the design life of the crawler chassis. , the sample duration of the load spectrum and the proportion of each working condition are used to calculate the fatigue damage values ​​of different nodes on the surface of the crawler chassis components under different working conditions. The load spectrum sample extension multiples for each working condition are calculated by the following formula: ， In the formula, Indicates the serial number of the sub-conditions. The value range is , is the total number of working conditions, For working conditions The load spectrum sample extension multiple, For working conditions The sample duration of the load spectrum under For working conditions The proportion of time in all working conditions; Any node on the surface of the crawler chassis components under different working conditions The fatigue damage value is calculated by the following formula: ， In the formula, For working conditions Surface nodes of lower track chassis components The fatigue damage value of For working conditions node Load spectrum sample fatigue damage value, is the node number, The value range is , is the total number of nodes; The load spectrum sample is the working condition part of the duration.

4. The fatigue life analysis method of engineering machinery crawler chassis according to claim 3 is characterized in that: The weighted value of fatigue damage of each node under each working condition is calculated by the following formula: ， In the formula, It is the weighted value of fatigue damage of each node in each working condition.

5. The fatigue life analysis method of engineering machinery crawler chassis according to claim 4 is characterized in that: The calculation of the overall fatigue life of the crawler chassis , including calculating the fatigue life of the crawler chassis at each node, taking the minimum value of the fatigue life of the crawler chassis at each node as the overall fatigue life of the crawler chassis ; The fatigue life of the crawler chassis at each node is calculated by the following formula: ， In the formula, For each node Fatigue life of track chassis; The overall fatigue life of the crawler chassis Calculated by the following formula: 。 6. The fatigue life analysis method of engineering machinery crawler chassis according to claim 1 is characterized by: The working condition simulation includes determining working condition influencing factors according to the working condition, combining multiple factors according to the driving speed, road surface, and posture, and simulating the actual working condition to perform working condition simulation; The obtaining of the multi-body dynamics model includes modifying the multi-body dynamics model. The modified multi-body dynamics model includes analyzing according to the determined simulation working conditions, extracting the track tension, driving wheel torque, and supporting wheel force, and modifying the mass distribution, moment of inertia, motion drive, and friction coefficient of the multi-body dynamics model by comparing with the actual measured forces in the test, so that the multi-body dynamics model of the whole machine is consistent with the actual measurement.

7. A method for correcting a crawler chassis of an engineering machinery, characterized in that: The fatigue life analysis method of a crawler chassis of an engineering machinery according to any one of claims 1 to 6 comprises: Design life , Overall fatigue life of track chassis and the actual service life of the crawler chassis Compare and determine the corresponding correction measures. , then improve the structure of components and reduce the stress in dangerous parts of components; select materials with strong fatigue resistance, use surface cold working hardening or surface heat treatment strengthening to generate residual compressive stress on the surface of parts.

8. The method for correcting the crawler chassis of an engineering machinery according to claim 7, characterized in that: The designed life , Overall fatigue life of track chassis and the actual service life of the crawler chassis The comparison of the above data will determine the corresponding corrective measures, including: like , the processing technology is controlled according to the pre-designed surface roughness of each component of the crawler chassis to control the generation of harmful surface residual tensile stress during the manufacturing process of the parts; when using the crawler chassis, avoid and reduce the corrosion during operation, avoid sudden increase in load due to misoperation; regular maintenance is carried out to prevent fatigue and wear failure of the crawler chassis products; According to the complex and variable loads in actual use, correct the other coefficients shown , recalculate the overall fatigue life of the track chassis , so that the overall fatigue life of the track chassis is recalculated Equal to actual service life ,at this time , then improve the structure of parts and reduce the stress in dangerous parts of parts; select materials reasonably and adopt strengthening technology, choose materials with stronger fatigue resistance, use surface cold working hardening or surface heat treatment strengthening to generate residual compressive stress on the surface of parts.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: include: Memory, for storing computer programs / instructions; A processor is used to execute the computer program / instructions to implement the steps of the engineering machinery crawler chassis fatigue life analysis method described in any one of claims 1-6 or the steps of the engineering machinery crawler chassis correction method described in any one of claims 7-8.

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