vibration

Vibration: Vibration is the oscillation phenomenon of quantities of motion (displacement, velocity and acceleration) in mechanical systems. Vibration is divided into two types: sinusoidal vibration and random vibration.
Sinusoidal vibration: periodic motion whose motion law can be expressed by a sinusoidal function expression. For example, all vibrations produced by rotation, pulsation, and oscillation (occurring on ships, aircraft, vehicles, and space vehicles) are sinusoidal vibrations.

Random vibration: Vibration whose instantaneous value cannot be predetermined for any given moment in the future. In a general transportation environment, the vibration environment generated by vehicles during transportation is random vibration. Even at the same time, there are different vibration amounts at different frequencies. When performing a random wave vibration test, Because there are vibration values ​​at different frequencies at the same time.

Testing purposes

Vibration test: The purpose of the vibration test is to simulate a series of vibration phenomena, test whether the product can withstand the vibration environment during transportation or use during its life cycle, and also determine the requirements for product design and function. The essence of the vibration test is to confirm the reliability of the product, screen out defective products in advance before leaving the factory, and evaluate the failure analysis of the defective products to make them high-level, high-reliability products.

Sine vibration test: The purpose of the sine vibration test is to simulate the vibration and effects experienced by electrical and electronic products during transportation, storage, and use in the laboratory, and to assess their adaptability.

standard test

Sinusoidal vibration test:

GB/T 2423.10-2019 Environmental testing of electrical and electronic products Part 2: Test method Test Fc: Vibration (sinusoidal)

IEC 60068-2-6-2007 Basic Environmental Testing Procedure. Part 2: Test. Section 6: Test Fc: Vibration (sine wave)

Random vibration test:

GB/T 2423.56-2018 Environmental testing of electrical and electronic products Part 2: Test methods Test Fh: Broadband random vibration (digital control) and guidelines

IEC 60068-2-64-2019 Basic Environmental Test Procedures. Part 2-64: Test. Test Fh: Vibration, broadband random sampling

(6) Mechanical impact
Shock: A phenomenon in which a system is subject to transient excitation and its force, position, velocity or acceleration changes suddenly. The impact is a sudden and violent energy release, energy conversion and energy transfer. The duration of the impact is short; the impact process is completed at one time and does not show periodicity. These characteristics of impact determine that impact environmental sources exist everywhere during the circulation and use of products. Usually the impact environment comes from mechanical impact between elastomers. Or it refers to the non-regular and non-repetitive impact force encountered during the impact process. The acceleration generated by this impact force is larger and the duration of the impact pulse is shorter. For example, braking and falling of a car during operation, recoil when a weapon is fired, and explosion of artillery shells on the ground are all impact phenomena, also called impact environments.
Impact Effects: Mechanical impact can have deleterious effects on the structural and functional integrity of the entire equipment. Generally, the extent of harmful effects increases with the magnitude and duration of the environmental impact. When the duration of the impact is consistent with the natural frequency of the equipment or the main frequency part of the input impact environment waveform is consistent with the natural frequency of the equipment, the harmful effects on the structure and functional integrity of the equipment will be amplified.

Types of impact and what the laboratory can do:

① Half sine

② Trapezoidal wave (square wave)

③ Triangular wave (front sawtooth wave and rear sawtooth wave)

Testing and its purpose
The impact test is mainly used to determine the ability of electrical and electronic components, equipment and other products to withstand non-repeated mechanical impacts during use and transportation to evaluate their adaptability to the impact environment and structural integrity. Secondly, it is used for In-house strength testing of microelectronic devices. Impact testing can also be used as a means of satisfactory product design and quality control.

Common test methods are: 18g/6ms, 100 times in each direction, impacting the product in 6 directions.

Common test standards include:
GB/T 2423.5-2019;

IEC 60068-2-27-2008;

(7) Collision
Testing and its purpose
Crash testing is mainly used for components, equipment and other products that may be subject to repeated collisions during transportation and use. The purpose is to determine whether components, equipment and other products are subject to repeated collisions during use and transportation. Adaptability to sexua-l mechanical impact and evaluate its structural integrity. At the same time, the crash test can also be used as a means of product satisfaction and quality control.

Common test standards include:
GB/T 2423.5-2019;

IEC 60068-2-27-2008;

(8) Fall
definition
A test performed on a product that involves a fall from a certain height to a test surface.
Testing and its applications

Confirm the suitability of the product to drops due to rough handling during handling, or confirm the minimum level of firmness used for safety requirements.

Common test methods are: 1m height, the product is dropped in 6 directions, 1 time/direction, and the drop position is cement board.

Common test standards include:
GB/T 2423.7-2018 IEC 60068-2-31-2008;