A method for exploring the vibration response of the cab floor of a shovel based on Hyper Mesh simulation

Abstract

The application relates to a method for exploring the vibration response of the floor of the cab of a wheel excavator based on Hyper Mesh simulation, and belongs to the technical field of related parameter testing of engineering machinery. In the method, an acceleration sensor is arranged on the floor of the cab of the wheel excavator, and meanwhile, all experimental equipment is arranged; then, the wheel excavator is started to begin testing, the vibration signal of the floor of the cab under an idling condition is measured, and after the experimental data are processed, the vibration acceleration spectrum diagram of the floor of the cab is obtained through drawing software; a three-dimensional model of the cab with the same size as the appearance size of the actual vehicle is established, is simplified and is imported into Hyper Mesh software to perform geometric cleaning; after the three-dimensional model of the cab is processed, the finite element model of the cab is obtained, the finite element model is calculated, and finally, the structural modal vibration mode diagram of the cab is obtained; by comparing the vibration signals of the floor of the cab in the actual vehicle test and the Hyper Mesh simulation, the accurate vibration response of the floor can be determined.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of testing related parameters of engineering machinery, and particularly relates to a method for exploring vibration response of a floor of a cab of a excavator based on HyperMesh simulation. BACKGROUND

[0002] As one of important engineering machinery, the noise and vibration problem of the excavator in use process increasingly attracts people's attention. First, the noise of the excavator can cause potential threat to the physical and mental health of the operator. Long-term exposure to high noise environment, the operator can be affected by hearing impairment and work efficiency reduction, and even cause work safety accidents. The noise in the cab of the excavator comes from many sources, mainly from the engine and the hydraulic system, which enters the vehicle through various apertures of the cab.

[0003] Therefore, it is very urgent to improve the NVH (Noise, Vibration, Harshness) performance of the cab of the excavator and improve the noise and vibration problem. The noise control research of the cab of the engineering machinery started late, and mostly refers to and learns from the noise control means in the car, but in recent years, more scholars have engaged in the research work of the noise and vibration problem of the engineering machinery. However, at present, many scholars study the noise and vibration characteristics of the cab from a single modal analysis simulation method or an experimental method, and few combine the two methods to finally determine the vibration response of the floor of the cab of the excavator by comparing the conclusions of the two methods. Therefore, how to determine the accurate vibration response of the cab of the excavator under the fixed condition has become an engineering technical difficulty to be solved. SUMMARY

[0004] The present application aims at solving the problems in the prior art, and provides a method for exploring vibration response of a floor of a cab of a excavator based on HyperMesh simulation.

[0005] In order to achieve the above object, the technical scheme of the present application is: a method for exploring the vibration response of the cab floor of a wheel excavator based on HyperMesh simulation, acceleration sensors are arranged on the cab floor of the wheel excavator, the wheel excavator is started to begin testing, the vibration signals of the cab floor under the idling condition are measured, and the vibration acceleration spectrum of the cab floor is obtained through drawing software after data processing; a three-dimensional model of the cab with the same size as the wheel excavator is established, is simplified, and is imported into the HyperMesh software for geometric cleaning; after the steps of mesh division, connection relationship setting, material and attribute assigning of each component of the three-dimensional model of the cab are sequentially performed, the finite element model of the cab is obtained, the finite element model is calculated, and finally the structural modal vibration mode diagram of the cab is obtained; the vibration signals of the cab floor of the real vehicle test and the HyperMesh simulation are compared, and the accurate vibration response of the cab floor is determined.

[0006] In an embodiment of the present application, the method comprises the following steps:

[0007] Step S01, providing a small wheel excavator and test instruments and equipment;

[0008] Step S02, arranging the position of the acceleration sensor on the cab floor of the wheel excavator;

[0009] Step S03, starting the wheel excavator and controlling the speed at the idling condition for testing;

[0010] Step S04, measuring the vibration signals of the cab floor;

[0011] Step S05, establishing a three-dimensional model of the cab according to the same size of the cab of the wheel excavator in step S01;

[0012] Step S06, simplifying the three-dimensional model of the cab, and then importing it into the HyperMesh software for geometric cleaning;

[0013] Step S07, mesh division is performed on each component of the three-dimensional model of the cab, and the mesh quality is checked;

[0014] Step S08, setting the connection relationship between each component of the three-dimensional model of the cab;

[0015] Step S09, assigning materials and attributes to each component of the three-dimensional model of the cab, and completing the establishment of the finite element model of the cab;

[0016] Step S10, calculating the established finite element model to obtain the corresponding modal parameters;

[0017] Step S11, compare the cab floor vibration signal obtained by the real vehicle test and the cab floor modal vibration mode chart in the Hyper Mesh simulation, and determine the actual vibration condition of the cab floor together.

[0018] In an embodiment of the present application, the instrument equipment in step S01 is specifically a data collector, four one-way acceleration sensors and a notebook computer.

[0019] In an embodiment of the present application, step S02 specifically comprises: installing one one-way acceleration sensor at each of the four connection positions of the front left, front right, rear left and rear right of the cab to measure the vertical vibration, and fixing the one-way acceleration sensor on the cab floor by gluing, and connecting each one-way acceleration sensor with the data collector through a data line.

[0020] In an embodiment of the present application, step S03 specifically comprises: starting the wheel excavator, controlling the engine speed of the wheel excavator at idle speed by the operator, waiting for the wheel excavator to reach a stable state after running for a period of time, and then starting data collection, continuously collecting three groups of data, each group of data collection time is 10s, and after the three groups of data are collected, the wheel excavator is turned off.

[0021] In an embodiment of the present application, step S04 specifically comprises: exporting the three groups of data of the vibration signal of the cab floor measured in the experiment, taking the average value under the premise of removing abnormal data to obtain the final experimental data, then importing the experimental data into Origin to draw a data graph, and finally obtaining the vibration acceleration frequency spectrum graph of the four points of the cab floor.

[0022] In an embodiment of the present application, step S05 specifically comprises: first drawing a part drawing of all components of the entire cab in the three-dimensional drawing software Solidworks, then assembling the part drawing to obtain a three-dimensional model of the cab.

[0023] In an embodiment of the present application, step S06 specifically comprises: ignoring the components in the three-dimensional model of the cab which have low contribution to the mechanical properties and structural deformation of the cab; then importing the simplified three-dimensional model of the cab into the Hyper Mesh software and performing cleaning work including stitching and repairing to solve the problem of missing geometric features of the imported three-dimensional model of the cab.

[0024] In an embodiment of the present application, step S07 specifically comprises: the parts of the cab are thin plate structures, so the parts are meshed by shell element, the middle surface of the parts is extracted, and then the mesh element is divided on the middle surface of the parts, wherein the mesh size is 5mm*5mm, and the operation is repeated until the mesh division of all parts is completed; then the mesh quality is checked according to the parameter standards including the warping degree and the length-width ratio in the mesh division standard.

[0025] In an embodiment of the present application, step S08 specifically comprises: the parts meshed by the mesh are connected, the ACM spot welding model simulated by the hexahedral element and the RBE3 element is used to simulate the spot welding connection, the pentahedral element with the RBE3 element is used to simulate the seam welding connection, and the hexahedral element with the RBE3 element is used to simulate the adhesive connection, until all parts are connected into a whole.

[0026] In an embodiment of the present application, step S09 specifically comprises: the material parameters of the parts of the cab are set in the material attribute card module of the Hyper Mesh software, the material attributes include the physical quantities of the elastic modulus, the Poisson's ratio and the density, and thus the complete finite element model of the cab is obtained.

[0027] In an embodiment of the present application, step S10 specifically comprises: the finite element model is solved by the OptiStruct solver in the Hyper Mesh, the Lanczos method is selected as the solving method, the card EIGRL is set to define the modal frequency range and the order of the modal shape to be solved, and thus the structural modal shape diagram of the cab is finally obtained through the solving calculation.

[0028] In an embodiment of the present application, step S11 specifically comprises: the floor vibration signal obtained by the real vehicle test is compared with the floor modal shape diagram in the Hyper Mesh simulation, it can be known from the vibration acceleration spectrum diagram of the cab floor that the acceleration values of the left front and right front positions of the cab floor are large, and the vibration is obvious, and it can be seen from the observation of the modal shape diagram of the floor that the vibration of the left front and right front positions of the cab floor is also large, the vibration conditions of the two positions are consistent, and the actual vibration condition of the cab floor is determined by the combination of the experiment and the simulation.

[0029] Compared with the prior art, the present application has the following beneficial effects: the vibration condition of the cab floor of the excavator is obtained by the mutual comparison and mutual verification of the experiment and the simulation, and the result is more accurate and reliable under the common verification of the experiment and the simulation. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The structural finite element model diagram of the cab and the floor of the excavator;

[0031] Figure 2 is a modal vibration mode diagram of the cab floor;

[0032] Figure 3 is a vibration acceleration frequency spectrum diagram of the cab floor;

[0033] Figure 4 is a flowchart of the embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be specifically described below with reference to the drawings.

[0035] The present application provides a method for exploring the vibration response of the cab floor of a wheel excavator based on Hyper Mesh simulation. Acceleration sensors are arranged on the cab floor of the wheel excavator, the wheel excavator is started to begin testing, the vibration signals of the cab floor under idling conditions are measured, and the vibration acceleration frequency spectrum diagram of the cab floor is obtained through data processing and drawing software. A three-dimensional model of the cab with the same shape and size as the wheel excavator is established, and is imported into the Hyper Mesh software after simplification for geometric cleaning. After the steps of mesh division, connection relationship setting, material and attribute assignment of each part of the three-dimensional model of the cab are sequentially performed, the finite element model of the cab is obtained, the finite element model is calculated, and finally the structural modal vibration mode diagram of the cab is obtained. The vibration signals of the cab floor of the real vehicle test and the Hyper Mesh simulation are compared to determine the accurate vibration response of the cab floor.

[0036] The following is the specific implementation process of the present application.

[0037] As shown in Figure 4 , the method for exploring the vibration response of the cab floor of the wheel excavator based on Hyper Mesh simulation proposed by the embodiment of the present application adopts the following specific optimization steps:

[0038] Step S01 specifically includes: preparing a small wheel excavator for testing, a B&K 3050 type data collector, four one-way acceleration sensors, and a notebook computer installed with BK Connect test analysis software.

[0039] Step S02 specifically includes: parking the excavator on a flat cement ground, then performing the sensor measurement point arrangement work, first finding the four bolt connection positions of the cab and the upper frame on the cab floor, which are located at the left front, right front, left rear and right rear of the cab floor, then respectively installing the acceleration sensors at the four connection positions, the installation method adopts adhesive connection, the sensor is connected to the channel of the data collector through the data line, and after ensuring that the sensor is installed firmly, the measurement point arrangement is completed.

[0040] Step S03 specifically includes: after the preparation work is completed, start the test, start the excavator, let the operator control the engine speed of the excavator at 1000r / min, i.e. in idle speed working condition, after reaching the speed, let the excavator run for a period of time, and after it reaches stability, start collecting data, use the timer to control the time, wait for 10s after the excavator is stable, record the first group of frequency domain signals in the software and name it as 1000_1, wait for another 10s and record the second group of signals and name it as 1000_2, wait for another 10s and record the third group of signals and name it as 1000_3, thus the data collection is completed, and the excavator is turned off.

[0041] Step S04 specifically includes: exporting the measured three groups of data to Excel, starting data processing, finding that the three groups of data at the left front position are normal, so the average value is taken as the final value; the first group of abnormal data is removed at the right front position, and the average value of the second and third groups is taken as the final value; the left rear position is processed in the same way as the right front position; the right rear position is processed in the same way as the left front position, and finally the processed data value is obtained, and the final data is imported into Origin to draw a vibration acceleration frequency spectrum diagram, as shown in Figure 3 .

[0042] Steps S05 and S06 specifically include: drawing part drawings of all components of the excavator cab in Solidworks, then assembling the part drawings to obtain a three-dimensional model of the excavator cab, then deleting the headlights, wipers, interior decoration and smaller bolt holes and other structures of the cab according to the requirements of finite element analysis; importing the model into Hyper Mesh in the form of Geometry Model, and for the problem of missing surfaces, the spline / Filler in the surfaces panel can be used to create missing surfaces.

[0043] Step S07 specifically includes: using the Mid mesh function in Hyper Mesh to automatically extract the middle surface of the cab plate and divide the grid, setting the grid size to 5mm×5mm in advance, repeating the operation to complete the grid division of all plates, and then checking the grid quality through the Element Quality function.

[0044] Step S08 specifically includes: making connection settings for the cab plate, setting spot welding connection according to connectors / spot, selecting acm(general) as the welding type; setting seam welding connection according to connectors / seam, selecting penta(mig) as the welding type; setting adhesive connection according to connectors / area, and selecting adhesives as the welding type.

[0045] Step S09 specifically comprises: creating materials in the model, establishing a first material named material_Q235, setting the elastic modulus E to 210000, the Poisson's ratio NU to 0.3, and the density RHO to 7.85e-09; establishing a second material named material_glass, setting the elastic modulus E to 72000, the Poisson's ratio NU to 0.17, and the density RHO to 2.2e-09, and applying to the corresponding parts respectively. Figure 1 The structure finite element model diagram of the excavator cab and the floor thereof is excavated.

[0046] Step S10 specifically comprises: solving and calculating the model by the OptiStruct solver in Hyper Mesh, selecting the Lanczos method with fast calculation speed and high result accuracy as the solving method, setting the card EIGRL, setting the SUBCASE, selecting the Normal modes as the analysis type, applying the EIGRL card therein, and finally solving and calculating the model by the OptiStruct solver. Figure 2 The modal vibration mode diagram of the cab floor.

[0047] Step S11 specifically comprises: comparing the floor vibration signal obtained by the real vehicle test and the floor modal vibration mode diagram in the Hyper Mesh simulation, and knowing from the vibration acceleration frequency spectrum diagram of the cab floor that the acceleration values of the left front and right front positions of the cab floor are larger, and the vibration is more obvious, and observing the modal vibration mode diagram of the floor can see that the vibration of the left front and right front positions of the cab floor is also larger, and the vibration conditions of the two positions are consistent, and the actual vibration condition of the cab floor is determined by combining the experiment and the simulation.

[0048] The patent is not limited to the above best embodiment, and anyone can derive other various forms of methods for exploring the vibration response of the excavator cab floor based on the Hyper Mesh simulation under the inspiration of the patent, and any equivalent changes and modifications made within the patent application scope shall belong to the coverage range of the patent.

Claims

1. A method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation, characterized in that, Accelerometers were placed on the cab floor of a wheeled excavator. The excavator was started for testing, and vibration signals from the cab floor were measured under idling conditions. After data processing, the vibration acceleration spectrum of the cab floor was obtained using plotting software. A 3D model of the cab, identical in dimensions to the actual excavator, was created, simplified, and imported into Hyper Mesh software for geometric cleanup. Following steps such as meshing, setting connection relationships, and assigning materials and properties to the components of the 3D cab model, a finite element model of the cab was obtained. The finite element model was then solved to obtain the structural modal shape diagram of the cab. By comparing the vibration signals from the actual vehicle test and the Hyper Mesh simulation, the accurate vibration response of the cab floor was determined. The method includes the following steps: Step S01: Provide a small wheeled excavator and the necessary testing equipment; Step S02: Position the acceleration sensor on the floor of the driver's cab of the wheeled excavator; Step S03: Start the wheeled excavator and test it while keeping the speed at idle. Step S04: Measure the vibration signal of the cab floor; Step S05: Create a 3D model of the cab with the same external dimensions as the cab of the wheeled excavator in step S01; Step S06: Simplify the 3D model of the cab and then import it into Hyper Mesh software for geometry cleanup; Step S07: Mesh the components of the 3D model of the cab and check the mesh quality; Step S08: Set the connection relationships between the various components of the 3D model of the cab; Step S09: Assign materials and properties to each component of the 3D model of the cab to complete the establishment of the finite element model of the cab; Step S10: Solve the established finite element model to obtain the corresponding modal parameters; Step S11: Compare the vibration signal of the cab floor obtained from the actual vehicle test with the modal shape diagram of the cab floor in the Hyper Mesh simulation to jointly determine the actual vibration of the cab floor; In step S01, the specific equipment consists of a data acquisition unit, four unidirectional accelerometers, and a laptop computer. Step S02 specifically includes: installing a unidirectional acceleration sensor at each of the four connection positions of the cab (left front, right front, left rear, and right rear) to measure vertical vibration. During installation, the unidirectional acceleration sensor is fixed to the cab floor with adhesive, and each unidirectional acceleration sensor is connected to the data acquisition unit via a data cable.

2. The method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation according to claim 1, characterized in that, Step S03 specifically includes: starting the wheeled excavator, having the operator control the engine speed of the wheeled excavator to idle, and after the wheeled excavator has run for a period of time and reached a stable state, starting to collect data. During the data collection, three sets of data are collected continuously, with each set of data collection lasting 10 seconds. After the three sets of data are collected, the wheeled excavator is turned off.

3. The method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation according to claim 2, characterized in that, Step S04 specifically includes: exporting three sets of data of vibration signals of the cab floor obtained by the experiment, averaging them after removing outlier data to obtain the final experimental data, and then importing the experimental data into Origin to draw data graphs, finally obtaining the vibration acceleration spectrum at four points on the cab floor.

4. The method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation according to claim 3, characterized in that, Step S05 specifically includes: firstly, drawing part drawings of all components of the entire cab in the 3D modeling software Solidworks, and then assembling the part drawings to obtain the 3D model of the cab; Step S06 specifically includes: ignoring components in the 3D model of the cab that have a low contribution to the mechanical performance and structural deformation of the cab; then importing the simplified 3D model of the cab into Hyper Mesh software and performing cleaning work including stitching and repair.

5. The method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation according to claim 4, characterized in that, Step S07 specifically includes: Since the components of the cab are thin-plate structures, shell element meshing is performed on the components. Mid-surface extraction is performed on the components, and then mesh elements are created on the mid-surface of the components, with a mesh size of 5mm × 5mm. This process is repeated until all components are meshed. Subsequently, the mesh quality is checked according to the meshing standards, including parameters such as warpage and aspect ratio. Step S08 specifically includes: Connection settings are configured for the meshed components. An ACM spot welding model simulated by hexahedral elements and RBE3 elements is used to simulate spot welding connections. Pentahedral elements with RBE3 elements are used to simulate seam welding connections, and hexahedral elements with RBE3 elements are used to simulate adhesive bonding connections, until all components are connected as a whole. Step S09 specifically includes: Material parameters for each component of the cab are set in the material property card module of the Hyper Mesh software. Material properties include physical quantities such as elastic modulus, Poisson's ratio, and density. This yields a complete finite element model of the cab.

6. The method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation according to claim 5, characterized in that, Step S10 specifically includes: using the OptiStruct solver in Hyper Mesh to solve the finite element model, using the Lanczos method as the solution method, setting the card EIGRL to define the modal frequency range and the order of the mode shapes to be solved, and finally obtaining the structural mode shape diagram of the cab through the solution calculation.

7. The method for investigating the vibration response of an excavator cab floor based on Hyper Mesh simulation according to claim 6, characterized in that, Step S11 specifically includes: comparing the floor vibration signal obtained from the actual vehicle test with the floor mode shape diagram in the Hyper Mesh simulation, and jointly determining the actual vibration of the cab floor through a combination of experiments and simulations.

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