A shock load occurred in a short time duration can lead to dangerous effect on the machine or structure. The use of conventional technique for shock vibration control by modifying the systems damping reduces the steady-state response of the system. However, this method fails to attenuate a large acceleration peak at the moment after the shock. An alternative method for reducing the maximum acceleration peak due to shock load using the principle of momentum exchange has been developed. When the shock excitation frequency is much larger in comparison with the main mass natural frequency, the passive momentum exchange impact damper(PMEID) produces good performance. However, the performance of PMEID decreases as the shock excitation frequency close to the main mass natural frequency. In this research, a simple technique to improve the performance of PMEID utilizing the pre-straining spring mechanism (PSMEID) is proposed. The dynamic model of the system with PSMEID is derived. Next, the simulation is conducted to evaluate the effectiveness of the proposed method.

Accurately and reliably measuring the gross weight and static load of the axles of moving vehicles, especially trucks, is important for preventing road damage and improving traffic safety and monitoring efficiency. This type of vehicle weight measurement is called "weigh-in-motion" (WIM). The conventional purpose of WIM is solely the estimation of the vehicle gross weight. However, WIM is also valuable for estimating the static axle load and the height of the vehicle's center of gravity, and possibly additional measurements. In this study, a method based on the averaging principle is proposed for signal processing in WIM systems. A preliminary experimental investigation, which involved two types of motorbikes and a light truck as test vehicles, and miniature plate-type measurement devices built by the authors, is presented. The gross weight and the static load of each axle of the vehicles, which traveled at various speeds up to approximately 40 km/h, are estimated with high accuracy.

This study proposes a new method for reducing the shock vibration response of an Unmanned Aerial Vehicle (UAV) during the landing process by means of the momentum exchange principle (MEID). The performance of the impact damper is improved by adding a pre-straining spring to the damper system. This research discusses the theoretical application of the damper to the UAV landing gear system. The UAV dynamics is first modeled as a simple lumped mass translational vibration system. Then we analyze a more complex two-dimensional model of UAV dynamics. This model consists of the main wheel, nose wheel and main body. Three cases of UAV landing gear mechanisms: without damper, with passive MEID (PMEID) and with pre-straining spring MEID (PSMEID) are simulated. The damper performance is evaluated from the maximum acceleration and force transmission to the main body. The energy balance calculation is conducted to investigate the performance of PSMEID. The simulation results show that the proposed PSMEID method is the most effective method for reducing the maximum acceleration and force transmission of UAV during impact landing.

A Combination of dynamic vibration absorbers (DVAs) consist of Tuned Mass Damper (TMD) and Tuned Liquid Column Damper (TLCD) for reducing vibration response of a two-DOF shear structure model is proposed. The absorber parameters are optimized using Genetic Algorithm (GA). The cost function is derived from the ratio between structure response and the excitation signal. The limitation in absorber space and fluid motion are considered during optimization process. The simulation results show that GA optimization procedure is effective to get the optimal absorber parameters in the case of limited absorber size and motion.

This research is aimed to design and analyze the performance of double dynamic vibration absorber (DVA) using a pendulum and a spring-mass type absorber for reducing vibration of two-DOF vibration system. The conventional fixed-points method and genetics algorithm (GA) optimization procedure are utilized in designing the optimal parameter of DVA. The frequency and damping ratio are optimized to determine the optimal absorber parameters. The simulation results show that GA optimization procedure is more effective in designing the double DVA in comparison to the fixed-points method. The experimental study is conducted to verify the numerical result.