CB 1146.9-1996 English PDF (CB1146.9-1996)
CB 1146.9-1996 English PDF (CB1146.9-1996)
See Chinese contents: CB 1146.9-1996
CB 1146.9-1996: Ship equipment environmental test and engineering guidance - Vibration (sinusoidal)
MINISTERIAL STANDARD OF
CHINA SHIPBUILDING CORPORATION
Replacing CB 1146.9-85
Ship equipment environmental test and engineering
guidance - Vibration (Sinusoidal)
ISSUED ON. DECEMBER 23, 1996
IMPLEMENTED ON. JUNE 1, 1997
Issued by. China Shipbuilding Corporation
Table of Contents
1 Subject content and application scope ... 3
2 References ... 3
3 Terms ... 3
4 Test conditions ... 4
5 Severity level ... 6
6 Test procedures ... 8
7 Test interruption handling ... 10
8 Qualification criteria ... 10
9 Test records and files ... 11
10 Engineering guidance ... 11
11 Details need to be specified when referencing this Standard ... 11
Annex A ... 12
Annex B ... 19
Ship equipment environmental test and
engineering guidance - Vibration (Sinusoidal)
1 Subject content and application scope
This Standard specifies the test conditions, severity, test procedures and acceptance criteria of environmental vibration (sinusoidal) test of ship equipment; and it provides the engineering guidance.
This Standard applies to the environmental test for evaluation of work adaptability and structural integrity of ship equipment under specified vibration conditions. 2 References
GB/T 2423.10-1995 Environmental testing for electric and electronic products - Part 2. Test methods - Test Fc and guidance. Vibration (Sinusoidal)
CB 1146.1-96 Ship equipment environmental test and engineering guidance - General rules 3 Terms
3.1 Fixed point
Point where test samples contact with fixtures or vibrating table, it is usually the places where fix the test samples when using. If a part of the actual installation structure is used for the fixture, it shall choose the contacting point of this part with vibration table as the fixed point, rather than the contracting point of the sample with installation structure. 3.2 Measuring point
Some specific points for data collection during test, the data collected are used for inspecting test parameters or controlling test parameters.
Note. Measuring points that are set to evaluate the performance of samples or to detect the vibration response characteristics of each part are not used as measuring points in this Standard. 3.2.1 Detection point
Points that are located in the fixtures, vibration table or samples, and are kept as closer as possible to the fixed points. If there are 4 or less than 4 fixed points, each of which can be taken as a detection point; if there are more than 4 fixed points, then the relevant standards shall specify 4 representative fixed points as the detection points.
Under special circumstances, such as large or complex samples, if the detection points are required to be at other places (not close to fixed points), then it shall be specified by relevant standards, or determined by test engineering.
When several small samples are mounted onto a fixture, or when a small sample having a number of fixed points, in order to derive the control signal, it can choose a single detection point, which shall be selected from the fixed points of samples and fixtures, not the fixed points of fixtures and vibration table. This is feasible only when the lowest resonant frequency exceeds the upper-limit of the test frequency after the sample is mounted onto the fixture. 3.2.2 Reference point
Points that are selected from the detection points, the signal at these points is used to control the test.
3.3 Control point
3.3.1 Single point control
Single point control is achieved by using the signal from the sensor at the reference points, so as to make the vibration parameters of this point remain within a specified range. 3.3.2 Multipoint control
Multipoint control is achieved by using the sensor signal at each selected detection point, and process the signal by continuous arithmetic average or comparison technique, so as to generate a control signal.
4 Test conditions
4.1 Characteristics requirements for vibration table
The vibration table shall have the following characteristics when it is mounted with fixtures and samples.
4.1.1 Basic movement
The basic movement shall be sinusoidal function of time; the fixed points of samples shall be basically the same, moving along parallel lines, and in accordance with the tolerance requirements of 4.1.2 and 4.1.3.
4.1.2 Lateral movement
Mast-area refers to the mast part; the main body refers to other parts except the mast part. If the known equipment is installed only on a particular ship, the upper frequency limit of test is the highest blade-frequency (the maximum rotating speed of propeller × number of blades ÷ 60) of this ship; if there are special requirements, it is specified by the relevant standards, specifications or order contract.
6 Test procedures
6.1 Initial inspection
Before the test, according to the specifications of product test outline or technical conditions, the sample shall be performed with appearance inspection, electrical and mechanical properties test; if it fails to meet the requirements, this test must not be performed. 6.2 Test conditions
Samples shall be performed with vibration response inspection and vibration durability test. For those performed with sweep-frequency durability test only, the above-mentioned two tests can be combined into one.
Unless otherwise specified in product standards or technical documents, these two tests shall be performed on three mutually perpendicular axels. The test sequence is that, two tests can be performed in one axial and then in another axial; or one test is performed in three axels and then perform another test in three axels.
6.2.1 Vibration response inspection
According to the amplitude specified in Table 1, within the test frequency range, from low frequency to high frequency, and then from high frequency to low frequency; sweep back and forth at a rate of one octave per minute, for 1 to 2 times.
Unless otherwise specified in product standards or technical documents, during the vibration response inspection, the sample shall be at normal working condition; If the mechanical vibration characteristics can not be determined because the sample is at working condition, then this sample shall be performed with additional response inspection at non-working condition.
During vibration response inspection, it shall test the vibration response of main structure and internal partial structure of the sample; and visually inspect the current, voltage and other performance changes indicated on indicating instrument or observed by other performance teat method, so as to judge the critical frequency of the following phenomenon. a. there are faults and (or) performance degradation of samples;
b. mechanical resonance or other response phenomenon.
6.3 Intermediate inspection
During the condition test, it shall test the main performance of samples. 6.4 Recovery
When it is required by the relevant specifications, at the end of condition test, it shall provide a period of recovery time, so as to make the sample recover to the same test conditions as that of initial detection.
6.5 Final inspection
After recovery, according to the specifications of product test program or technical documents, perform appearance inspection, electrical performance and mechanical performance to the samples.
7 Test interruption handling
During test, if there are great faults, such as structural damage or malfunction, that are out of the permitted range of product test program or technical conditions, the test shall be interrupted. After being repaired, repeat the vibration test; the sample provider can provide new samples for retest.
If there are non-repeating faults that can be easily replaced or repaired, such as indicating- light and component damage AND welding defects, the test shall be also interrupted. After being repaired, repeat only the test items that have faults; repeating the whole vibration test is not required.
No matter what kind of test interruption above occurs, it shall be described in detail in the test report.
8 Qualification criteria
Test samples without the following faults during test and after test can be deemed as qualified. a. mechanical damage or injury that influence the completion of main functions; b. during final inspection, there is a performance indicator that fails to meet the requirements;
c. during final inspection, all performance indicators meet the requirements, but during vibration response inspection and sweep-frequency dura...