This standard specifies the data collection conditions and methods for the dynamic response of local structures, mechanical devices or equipment of ships that are larger than the vibration of the hull beam at the location, as well as the expression form of data reports. This standard is applicable to ships sailing at sea. It can also be used as a reference for inland ships. GB/T 14697-1993 Ship Local Vibration Measurement Procedure GB/T14697-1993 Standard Download Decompression Password: www.bzxz.net

UDC 629 : 534. 1. 08
National Standard of the People's Republic of China
GB/T14697—93
Code for the measurement of local vibration of ship
Promulgated on November 9, 1993
National Technical Supervision Bureau
Implementation on July 1, 1994
W.National Standard of the People's Republic of China
Code for the measurement of local vibration of ship
GB/T 14697 .-93
This standard adopts the international standard ISO4858-84 "Specification for the measurement and evaluation of local vibration data of ship structures and equipment". Main content and scope of application
This standard specifies the data collection components and methods for the dynamic response of local structures, machinery or equipment of ships, as well as the form of data reporting. This standard is applicable to ships sailing at sea. It can also be used as a reference for inland ships. 2. Measuring instruments
2.1 An electronic measuring system with multi-channel and long-term record storage should be selected. It consists of sensors, amplifiers, filters and recorders.
2.2 It should have a relatively good frequency range and amplitude linearity, meet the frequency value requirements of the measured components, and be able to adapt to environmental conditions such as temperature, visibility and noise on board.
2.3 The sensor should be installed firmly, in the right direction, and the wire direction and layout should be reasonable. 2.4 The sensitivity, amplitude characteristics, amplitude linearity and frequency characteristics of the instrument must be regularly checked or calibrated, and can only be used after obtaining a certificate.
2.5 When the pulse device is installed on the propeller shaft, the pulse signal must correspond to the upper dead center of the main engine No. 1 cylinder or a certain position of the propeller. 2-6 Under the premise of meeting the test requirements, a portable electric instrument or a mechanical vibration meter for single-point measurement can be used. 3 Measurement conditions
3.1 The water depth is not less than 5 times the draft of the ship. When it is confirmed that fresh water does not affect the test results, the test can also be carried out at the dock. 3.2 The engine should be below level 3.
3.3 The ship should be fully loaded or unloaded. When ballasted, the draft should ensure that the propeller is completely immersed in water. 3.4 The ship should maintain a stable navigation and the steering angle should be limited to ±2°. The main engine and other mechanical equipment are in a stable working state. In the case of a multi-propeller ship, the speed of each shaft should be kept consistent or even consistent. 3.5
3.6 If necessary, individual machinery can be operated separately. 3.7 The conditions that cannot meet the above conditions shall be noted in the quotation. 4 Measurement location
The aft end of the longitudinal midplane of the upper (main) deck or the front of the aft peak tank is the main representative point of the ship's vibration. The measurement directions are vertical, transverse and longitudinal. Current rate 1.
Approved by the State Administration of Technical Supervision on November 9, 1993 and implemented on July 1, 1994
W4.2 Superstructure
Instrument location
GB/T14697-93
Figure 1 Schematic diagram of upper measurement points
4.2.1 The intersection of the centerline of the bridge deck and the front wall. The measurement directions are vertical, transverse and longitudinal. 4.2-2 The intersection of the centerline of the middle plate of the navigation cabin and the upper (high) deck and the centerline of the front wall. The measurement direction is transverse and longitudinal. 4.2.3 The intersection of the centerline of the upper (main) deck and the front wall. The measurement direction is transverse and longitudinal, see Figure 2. Vertical
Special sensor position
Figure 2 Schematic diagram of superstructure measurement points
4.3 Local components
At the location with local vibration, such as components, superstructure components (smoke, rod, compass seat, pipeline), deck, compartment, foundation, etc. The measurement direction depends on the situation of the unit. See Figure 3 for the gun rod measurement point. W.4.4 Mechanical attack
GE/T 14697—93
Figure 3 Schematic diagram of gun rod measurement points
At the measurement point on the surface of the machine with large amplitude. The measurement direction is vertical, transverse and longitudinal 4.5 Hull pulsation force measurement point (optional)
Set one measurement point on the intersection of the vertical plane of the propeller and the outer bottom plate. Set four measurement points on the intersection of the plane where the propeller disk is located and the outer bottom plate. For specific arrangements, see 4. D in the figure is the schematic diagram of the pulsation pressure measurement point at the center of the propeller's forward axis
4.6 Structural dynamic stress measurement point (optional)
For the measured local structure, arrange unidirectional or plane stress measurement points according to specific requirements. 4. For cabins
. GB/T 14697-93
For instrument rooms, chart rooms and other cabins with obvious local dynamics, arrange measurement points according to specific requirements. 4.8 The above measurement positions are given based on the principle of one-share. Under different conditions, the selection of measurement positions should be consistent with the measurement purpose. Measurement parameters
Measurement parameters should include:
Displacement, mm;
Speed, mm/53
Such as speed.rim/s
Pressure+MPa;
Stress, MPa:
Frequency.Hz:
Phase, ()
a.~e.All are expressed as single peak value.
6 Measurement procedures
6.1 Calibration
6.1.1After all the measuring instruments are installed and connected on site, each channel must be powered on and debugged, and the appropriate process must be selected to ensure normal operation. 6.1.2Before and after the measurement, each channel shall be calibrated on site to repeat the system calibration status in the laboratory and keep good on-site records. 6.2 Test Implementation
6.2.1 During the test, the speed of the machine starts from half of the rated speed, and the speed of the low-speed machine is 5~-10r/min, the medium-speed machine is 10~50r/min, and the high-speed machine is 50~1001/min. The speed is gradually increased until the rated speed is reached. The speed gears should be appropriately close near the resonance speed and the operating speed. The test should be carried out after the speed of each gear is stable. 6-2.2 If necessary, special measurements should be made at some speeds where local vibration occurs. 6-2.3 During the local structure excitation test, steady-state excitation or dynamic excitation can be used to obtain the modal parameters required by the structure under test (optional).
7 Data acquisition, analysis and provision
7.1 Data acquisition
7.1-1 The continuous time of signal delay recording shall not be less than 607.1.2 The recording length of the optical oscilloscope shall contain at least 100 base units. 7.1.3 When recording the test data, the pulse signal and the vibration response signal must be recorded synchronously. 7.2 Data analysis
7.2.1 Random truncation or whole cycle truncation method can be used for computer analysis. 7.2.2 The sampling time AT of the fast Fourier transform (FFT) is generally 4s. The frequency resolution A/ is calculated as follows: AF
The formula is: frequency resolution. H
△T---sample time, 5.
7.2.3 The 10-value method is used for the analysis. For example, from 10 base waveforms, 10 vibration values ​​are selected and averaged as the maximum vertical amplitude.
7.3 Data provision
7.3.1 Provide the vibration amplitude of each order at the start-up point of the rest frame at each propeller speed. 7.3.2 Provide the shaft control caused by the propeller and the amplitude of each order of vibration of the local drilling structure and mechanical equipment. WGB/T 14697—93
7.3.3 Provide the vibration amplitude of the main frequency components caused by the local structure and mechanical device. 7.3.4 Provide the modal parameters required by the test piece for the local component excitation test. 7.3.5 If required, further analyze the source of the serious local perturbation. 7.3.6 When there is "slap vibration", the frequency and maximum and minimum amplitude of the "slap" shall be provided. 8 Data report
8.1 Main design parameters of the ship.
8.1.1 The main parameters of the propulsion device of the new ship can be read according to the Appendix A (reference material) Table A1 and A2. 8.1.2 Provide the structural surface of the hull and superstructure. 8.2 Measurement point map.
8.3 Test conditions shall be filled in according to the Appendix A (reference material) Table A3. 8.4 Vibration measurement results can refer to Appendix A (reference material), Table A1 Fill in. 8.5 Provide the analysis method of the test data.
8.6 According to the corresponding valuation standards, evaluate the measurement results according to Figure 5. 0m
Figure 5 Ship's dynamic data plot
W Ship name
Manufacturer/contractor Year
Ship and model
Structural type
Maximum line width m
Breadth B+m
Draft (full load) d+m
Displacement (full load)t
Square coefficient C
Load capacity, m
Middle scraping surface moment of inertia, m
Middle section shear area, m
Middle section schematic
GB/T 14697 .. 93
Appendix Abzxz.net
Example of data table for local vibration measurement of ships (reference)
Table A1 Main parameters of test ship
Number, engine type and model
Year of construction
Crown diameter and stroke, nrn
Number of cylinders
Power, kw
Speed, r/min
Unbalanced force||t t||Diameter, m
R and propeller type
Rear speed, r/min
Blade angle, (\)
Pitch ratio
Question ratio
Cabin type and number
Propeller hull cost business diagram
W6
Pile reverse material system must be taught
Rotating part
GB/T 14697—93
Table A2 Main parameters of the shaft system
Maximum speed and common speed+1/min
Bushing material model
Vehicle alignment (joint or theoretical alignment)
Stationary part
Height diameter.m4Length 1mt
First intermediate yoke
Second intermediate shaft
Third intermediate yoke
Fourth intermediate shaft
Third ...
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