Accelerated Sine-on-Random Vibration Test Method of Ground Vehicle Components over Conventional Single Mode Excitation

Abstract

Automotive manufacturers typically assess the mechanical durability performance of ground vehicle components for vibration excitation using either random or harmonic spectral loading patterns, such as the loading patterns suggested in international standards (e.g., ISO-16750-3). Selection of the correct excitation profile is dependent on the service condition of the component of interest. However, in the instance where the vehicle component is exposed to both harmonic excitations and background noise, the severity of impact of the in-service environment cannot be satisfied via a single random or harmonic test alone. In this case, the optimal test strategy is to evaluate the vehicle component under a sine-on-random excitation. Within this study, a uniaxial excitation test was conducted for a notched simple specimen under three spectral loading cases (harmonic, random, and sine-on-random), and the test severity was determined based on two kinds of fatigue damage: the physical damage from measured strain and the calculated pseudo-damage from acceleration measurements, as indicated in ISO-16750-3. Based on this comparison of accumulated fatigue damage, the efficiency of the proposed sine-on random vibration was proved against conventional single spectral pattern test methods.

Sensitivity Analysis of the Frequency Response Function of Carbon-Fiber-Reinforced Plastic Specimens for Different Direction of Carbon Fiber as Well as Spectral Loading Pattern

“…Combined with its excellent specific strength, CFRPS have received much attention for application in mechanical products. Previous studies verified that the dynamic response changes according to the spectral loading patterns for conventional steel material in the uniaxial excitation test [20,21]. If CFRPs exhibit different damping characteristics under different excitation profile conditions, then differences in absolute values could inevitably cause errors larger than those of other materials.…”

“…Thus, the natural frequency ωn,i should be expressed by ωn,i(θ), according to the different directions of the carbon fiber. On the other hand, a previous study showed that the coefficient of damping changes according to the spectral loading of external force for a simple specimen with S45C [20,21]. It is also well recognized that the damping coefficient of CFRP materials is much higher than that of conventional steel materials [17,18,19].…”

Analysis of Powertrain Loading Dynamic Characteristics and the Effects on Fatigue Damage

“…The simulation results of the three strategies will be compared by evaluating component fatigue damage with a pseudo-S-N curve, which is applicable in two conditions: one is that the real S-N curve of the material or the component is unknown, and the other is that the calculated fatigue damage is zero when the interests are infinite-life designed. If the pseudo-S-N curve has the same slope as the real one, the calculated pseudo-damage value can evaluate the intensity of the loading on the components concerned relatively [20]. In this paper, the estimated pseudo-S-N curve is set as slope factor k = 5.23, referring to the recommended method in reference [21].…”

Acceleration factor and experimental validation of aluminum alloy under narrow‐band random excitation

“…Wang and Wang 6 and Shires 7 studied the solution of the acceleration factor under broadband non‐Gaussian distribution by introducing the concept of the G rms – N curve. Kim 8 conducted uniaxial accelerated vibration tests under three loading conditions and carried out relevant studies on accelerated vibration tests. Ozsoy et al 9 calculated the acceleration factor according to the PSD of the accelerated excitation spectrum and carried out accelerated vibration tests of aerospace components.…”