Stress testing method for heavy mechanical equipment

Abstract

A stress test method for heavy mechanical equipment comprises the steps that firstly, an ultrasonic measurement assembly is installed on the mechanical equipment and comprises an ultrasonic generator and an ultrasonic receiver which are oppositely arranged on the two sides of a measurement position, then ultrasonic waves are sent to the ultrasonic receiver through the ultrasonic generator, and an initial stress value is obtained through an ultrasonic critical refraction longitudinal wave stress test; mounting a strain gauge on the mechanical equipment to continuously perform stress test to obtain a relative stress curve changing along with time, adding the initial stress value and the stress value at each moment in the relative stress curve, and performing zero setting on the relative stress curve to obtain the stress value of the mechanical equipment. The real stress state of the measuring point is calculated by combining the ultrasonic critical refraction longitudinal wave stress testing result and the strain gauge stress testing result, the real stress curve of the measuring position is obtained, implementation is convenient, cost is low, and the defect that the strain gauge stress testing technology cannot accurately measure the real stress of the heavy mechanical equipment is overcome.

Description

Technical Field

[0001] The invention relates to the field of mechanical equipment stress testing, and in particular to a stress testing method for heavy mechanical equipment. Background Art

[0002] Strain gauge stress testing technology can be used to measure the relative stress generated by mechanical equipment during operation or under the influence of the environment. The principle is to use the strain gauge laid on the surface of the measured object to generate micro-strain synchronously with the measured object, establish the relationship between the strain of the measured object and the change of the strain gauge electrical signal, and then calculate the stress result of the measured object by processing the change of the strain gauge electrical signal.

[0003] The existing stress testing method requires the strain gauge's initial stress to be zeroed before starting to record stress data. For most small mechanical equipment, the initial stress of the equipment during the zeroing operation can be ignored relative to the working stress. However, if the test object is heavy mechanical equipment, it will be subject to loads such as its own weight, so that the initial stress of the equipment during the zeroing operation is too large to be ignored. At this time, the stress value measured by the strain gauge stress testing equipment will have a large deviation from the true stress value, which will lead to inaccurate principal stress results obtained by subsequent calculations. However, there is no simple and effective method in the prior art to improve accuracy. Summary of the invention

[0004] In order to solve the problem that the existing stress testing method is insufficiently accurate for heavy machinery and equipment, the present invention provides a stress testing method for heavy machinery and equipment.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a stress testing method for heavy machinery equipment, comprising the following steps: Step 1: Install an ultrasonic measurement assembly on the mechanical equipment, including an ultrasonic generator and an ultrasonic receiver relatively arranged on both sides of the measurement position, and then send ultrasonic waves to the ultrasonic receiver through the ultrasonic generator to perform an ultrasonic critical refraction longitudinal wave stress test; The ultrasonic generator sends an analog signal to the analog-to-digital converter while emitting ultrasonic waves, and the ultrasonic receiver sends an analog signal to the analog-to-digital converter while receiving ultrasonic waves. The analog-to-digital converter converts the analog signal into a digital signal and transmits it to the PC. The PC calculates the initial stress value at the measuring position based on the time difference between the digital signals received successively. Step 2: Install the strain gauge on the mechanical equipment, attach the strain gauge to the measurement position and ensure that the measurement axis of the strain gauge coincides with the emission direction of the ultrasonic wave in step 1, and then continue to perform stress testing through the strain gauge; The strain gauge transmits the analog signal of the deformation to the analog-to-digital converter, which converts the analog signal into a digital signal and transmits it to the PC. The PC calculates the real-time measured stress value based on the received digital signal and generates a relative stress curve that changes with time based on the continuously obtained stress value. Step 3: Add the initial stress value and the stress value at each moment in the relative stress curve respectively, so as to zero the relative stress curve and obtain the true stress curve at the measuring position.

[0006] Preferably, the ultrasonic generator and the ultrasonic receiver are respectively connected to the ultrasonic processing analog-to-digital converter and transmit signals, and the ultrasonic processing analog-to-digital converter is connected to the ultrasonic processing PC and transmits signals; The strain gauge is connected to the strain processing analog-to-digital converter and transmits signals, and the strain processing analog-to-digital converter is connected to the strain processing PC and transmits signals.

[0007] Preferably, when there are multiple measurement positions, multiple ultrasonic measurement components and multiple strain gauges are installed on the mechanical equipment, the multiple ultrasonic measurement components are connected to the ultrasonic processing analog-to-digital converter, and the multiple strain gauges are connected to the strain processing analog-to-digital converter. After calculation by the ultrasonic processing PC and the strain processing PC, the true stress curves of the multiple measurement positions are obtained respectively.

[0008] Preferably, in step 2, before installing the strain gauge, the ultrasonic generator and the ultrasonic receiver are removed.

[0009] According to the above technical solution, the beneficial effects of the present invention are: The present invention firstly performs a test through an ultrasonic measurement component, adopts an ultrasonic critical refraction longitudinal wave stress test method, calculates an initial stress value, then performs a continuous test through a strain gauge to obtain a relative stress curve that changes with time, and finally adjusts the relative stress curve to zero through the initial stress value, combines the ultrasonic critical refraction longitudinal wave stress test result and the strain gauge stress test result, calculates the true stress state at the measuring point, and obtains the true stress curve at the measuring position. The invention is convenient to implement and has low cost, and overcomes the defect that the strain gauge stress test technology cannot accurately measure the true stress of heavy machinery and equipment. The ultrasonic critical refraction longitudinal wave stress test equipment is a non-destructive test method, which will not affect the subsequent strain gauge stress test results, and finally effectively avoids the situation that the heavy machinery and equipment are affected by loads such as their own weight and it is difficult to adjust the strain test equipment to zero, thereby improving the accuracy of the stress test. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of embodiment 1; Figure 2 It is a schematic diagram of Embodiment 2; Figure 3 Schematic diagram of stress curve.

[0011] Markings in the figure: 1. Ultrasonic generator, 1-1. Ultrasonic generator No. 1, 1-2. Ultrasonic generator No. 2, 1-3. Ultrasonic generator No. 3, 2. Ultrasonic receiver, 2-1. Ultrasonic receiver No. 1, 2-2. Ultrasonic receiver No. 2, 2-3. Ultrasonic receiver No. 3, 3. Ultrasonic processing analog-to-digital converter, 4. Ultrasonic processing PC, 5. Strain gauge, 5-1. Strain gauge No. 1, 5-2. Strain gauge No. 2, 5-3. Strain gauge No. 3, 6. Strain processing analog-to-digital converter, 7. Strain processing PC, 8. True stress curve, 9. Relative stress curve. DETAILED DESCRIPTION

[0012] With reference to the accompanying drawings, the specific implementation is as follows: Embodiment 1, a stress testing method for heavy machinery equipment, comprising the following steps: Step 1: Figure 1 As shown, an ultrasonic measurement assembly is installed on the mechanical equipment, including an ultrasonic generator 1 and an ultrasonic receiver 2 relatively arranged on both sides of the measuring position, and then ultrasonic waves are sent to the ultrasonic receiver 2 through the ultrasonic generator 1 to perform ultrasonic critical refraction longitudinal wave stress test.

[0013] The ultrasonic generator 1 sends an analog signal to the ultrasonic processing analog-to-digital converter 3 while emitting ultrasonic waves, and the ultrasonic receiver 2 sends an analog signal to the ultrasonic processing analog-to-digital converter 3 while receiving ultrasonic waves. The ultrasonic processing analog-to-digital converter 3 converts the analog signal into a digital signal and transmits it to the ultrasonic processing PC 4. The ultrasonic processing PC 4 calculates the initial stress value of the measuring position according to the time difference of the digital signals received successively. In this embodiment, the initial stress value is taken as 15 MPa as an example.

[0014] Step 2: Install the strain gauge 5 on the mechanical equipment, attach the strain gauge 5 to the measuring position and ensure that the measuring axis of the strain gauge 5 coincides with the emission direction of the ultrasonic wave in step 1, and then continue to perform stress testing through the strain gauge 5. Before attaching the strain gauge 5, the ultrasonic generator 1 and the ultrasonic receiver 2 can be removed to avoid damage to the ultrasonic generator 1 and the ultrasonic receiver 2 when the equipment is in a harsh working condition.

[0015] The strain gauge 5 transmits the analog signal of the deformation to the strain processing analog-to-digital converter 6, and the strain processing analog-to-digital converter 6 converts the analog signal into a digital signal and transmits it to the strain processing PC 7. The strain processing PC 7 calculates the real-time measured stress value based on the received digital signal, and generates a relative stress curve 9 that changes with time based on the continuously obtained stress value.

[0016] Step 3: Add the initial stress value to the stress value at each moment in the relative stress curve 9, thereby adjusting the relative stress curve 9 to zero and obtaining the true stress curve 8 at the measurement position. Figure 3 As shown, in this embodiment, the initial stress value is 15 MPa, so the true stress curve 8 is equivalent to translating the relative stress curve 9 upward by a longitudinal distance of 15 MPa, so that the zero point of the relative stress curve 9 is equal to the initial stress value 10, which is also equivalent to increasing all stress values ​​calculated by the strain processing PC 7 by 15 MPa before generating the stress curve, and then generating the stress curve.

[0017] Embodiment 2 is different from Embodiment 1 in that in this embodiment, there are three measurement positions at the same time, so three ultrasonic measurement components and three strain gauges 5 are installed on the mechanical equipment, such as Figure 2 As shown, it includes a No. 1 ultrasonic generator 1-1 and a No. 1 ultrasonic receiver 2-1 that are relatively arranged, and a No. 1 strain gauge 5-1 located therebetween; a No. 2 ultrasonic generator 1-2 and a No. 2 ultrasonic receiver 2-2 that are relatively arranged, and a No. 2 strain gauge 5-2 located therebetween; a No. 3 ultrasonic generator 1-3 and a No. 3 ultrasonic receiver 2-3 that are relatively arranged, and a No. 3 strain gauge 5-3 located therebetween; the three ultrasonic measurement components are all connected to an ultrasonic processing analog-to-digital converter 3, and the three strain gauges 5 are all connected to a strain processing analog-to-digital converter 6. After calculations by an ultrasonic processing PC 4 and a strain processing PC 7, true stress curves 8 at the three measurement positions are obtained respectively.

[0018] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of use of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention should fall within the protection scope of the present invention, and the technical contents for which protection is sought in the present invention have all been recorded in the claims.

Claims

1. A stress testing method for heavy machinery equipment, characterized in that: The following steps are involved: Step 1: Install an ultrasonic measurement component on the mechanical equipment, including an ultrasonic generator (1) and an ultrasonic receiver (2) arranged on both sides of the measurement position, and then send ultrasonic waves to the ultrasonic receiver (2) through the ultrasonic generator (1) to perform an ultrasonic critical refraction longitudinal wave stress test; The ultrasonic generator (1) sends an analog signal to the analog-to-digital converter while emitting ultrasonic waves, and the ultrasonic receiver (2) sends an analog signal to the analog-to-digital converter while receiving ultrasonic waves. The analog-to-digital converter converts the analog signal into a digital signal and transmits it to a PC. The PC calculates the initial stress value at the measurement position based on the time difference between the digital signals received successively. Step 2: Install the strain gauge (5) on the mechanical equipment, attach the strain gauge (5) to the measurement position and ensure that the measurement axis of the strain gauge (5) coincides with the emission direction of the ultrasonic wave in step 1, and then continuously perform stress testing through the strain gauge (5); The strain gauge (5) transmits an analog signal of the deformation to an analog-to-digital converter, which converts the analog signal into a digital signal and transmits it to a PC. The PC calculates a real-time measured stress value based on the received digital signal and generates a relative stress curve (9) that changes with time based on the continuously obtained stress value. Step 3: Add the initial stress value and the stress value at each moment in the relative stress curve (9) respectively, so as to zero the relative stress curve (9) and obtain the true stress curve (8) at the measuring position.

2. A stress testing method for heavy machinery equipment according to claim 1, characterized in that: The ultrasonic generator (1) and the ultrasonic receiver (2) are respectively connected to the ultrasonic processing analog-to-digital converter (3) and transmit signals, and the ultrasonic processing analog-to-digital converter (3) is connected to the ultrasonic processing PC (4) and transmits signals; The strain gauge (5) is connected to the strain processing analog-to-digital converter (6) and transmits signals, and the strain processing analog-to-digital converter (6) is connected to the strain processing PC (7) and transmits signals.

3. A stress testing method for heavy machinery equipment according to claim 2, characterized in that: When there are multiple measurement positions, multiple ultrasonic measurement components and multiple strain gauges (5) are installed on the mechanical equipment, the multiple ultrasonic measurement components are connected to the ultrasonic processing analog-to-digital converter (3), and the multiple strain gauges (5) are connected to the strain processing analog-to-digital converter (6). After calculation by the ultrasonic processing PC (4) and the strain processing PC (7), the real stress curves (8) of the multiple measurement positions are obtained respectively.

4. A stress testing method for heavy machinery equipment according to claim 1, characterized in that: In step 2, before installing the strain gauge (5), the ultrasonic generator (1) and the ultrasonic receiver (2) are removed.

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