Indoor communication equipment operates 24/7 and is continuously exposed to repetitive ambient vibrations depending on operating conditions. In this example, we will explore how to verify whether durability safety is secured against repetitive vibration loads on communication equipment through frequency response analysis.
The topic we will cover today is "resonance" and "durability" of [roducts.
Photo of vibration table test
We always have these concerns when purchasing a product. "Will this product work well without breaking down?" "Is it good value for the price?" Naturally, consumers prefer products that offer good value for money and can be used comfortably without failure.
Conversely, those who design and manufacture products always face the same concerns. "Will my product be used without problems during the warranty period?" "Can I maintain durability while reducing the unit cost of the product?“ From a designer's perspective, it is essential to create a product that can be used without defects during the warranty period while reducing the unit cost.
Vibration exists in all equipment around us, including the base station communication equipment that is the subject of this topic. There may be internal vibrations from motors or fans inside the equipment, external vibrations caused by earthquakes or surrounding equipment, or special situations involving vibrations generated by passing cars or trains.
Various environmental vibrations exist in products, and there are situations where the shaking is visible to the eye or the noise is audible. When users actually encounter these phenomena in daily life, they feel anxiety about the usability of the product and its reliability drops significantly. Alternatively, the durability of the product may deteriorate, leading to failures within the warranty period.
For this reason, at the design stage we conduct vibration tests and reinforcement to determine whether the durability of the product is safe, what the maximum displacement is when resonance occurs due to coincidence of internal/external vibrations, and whether excessive noise is generated.
Vibration testing technology uses the concept of forced vibration to verify the structural response, and the Sweep-sine vibration test is commonly used.
Its purpose is to examine the resonance influence of a structure in the frequency range of interest and to determine its fatigue life. Resonance occurs when a product is exposed to external vibration that coincides with its natural frequency, and damage may occur due to the amplified vibration at that point. Therefore, identification of resonance frequencies is an essential element in product development and certification.
General component vibration testing requires long test durations ranging from several hours to several days, as well as expensive facility costs. To reduce the cost of such testing, an accelerated vibration test approach or a simulation-based approach can be used. The amplitude of the structural response relative to the amplitude of the applied vibration can be evaluated, and the vibration fatigue life can be predicted using the material's S-N curve.
Let us now explore how numerical simulation can be used to verify the durability of a product. The example model is a BBU (Base Band Unit) communication equipment installed at a base station, and the material reviews the actual product life by simulating the Sweep-sine test requirements of IEC-60068-2-6.