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The largest articulation inside human body is the knee joint which is composed by hard components, soft tissues and surrounded muscles. The knee is a mobile hinge, and it permits flexion, extension, slight internal and external rotation of the leg. The knee joint is vulnerable to both sharp injury and chronic osteoarthritis. Once have been injured, the knee joint is not easily restored. This study employs separately the experimental measurement, reverse engineering and finite element analysis to investigate the dynamic characteristics of intricate knee joint. The three-dimensional geometric model of each component of knee joint includes hard tissues and soft tissues. The hard tissues have femur, tibia, fibula, patella and the soft tissues have meniscus, patellar ligament, medial and lateral collateral ligament, a pair of cruciate ligaments, etc. Then the model is imported into ANSYS software. Via modal, periodic excitation and impact analysis, the dynamic characteristics of each component and the whole knee model are received. The fundamental mode shapes, natural frequencies and stresses of all the components of knee are also obtained. These normal modes are essential when investigating the dynamic motion of the whole knee. The results show that after impact, the soft tissues have larger displacement than that of the hard tissues. Consequently, the fracture occurs when the stretch which is caused by external force excess ultimate strength of the component. It also explains why the athletes frequently injure the ligaments and tendons of the knee or ankle during the intensive exercise. Therefore, by reducing the motion of articulation, the professional player could not only reduce the generated internal stresses in the tissue but also consequently lessen the chance of injury.

Golf is an extremely popular activity that over 60 million of people enjoy playing it. Overuse injuries associated with the back, neck, wrist, shoulder, elbow, knee, etc., are common for both professional and amateur player due to golf swing. A lot of researchers investigate the mechanical behavior of golf club or biological response of human body individually. But there is little study on the dynamic interaction between the hand-arm and golf club mashie (HAGCM) when striking ball. Solidworks package is used to draw the 3D geometric model of a left hand-arm contacted at the grip of the golf club. Then the 3D biomechanical model is imported into ANSYS software for transient (impact) analysis. Due to complicated geometry of the sharp edge at the club head and the hand-arm, the tetrahedral element is applied for all components of HAGCM to save computer resource during ANSYS process. Finite element convergence test is obtained before any further analysis. In order to simulate the ball-striking, the hitting surface of the club head is subjected to the impact force of 22 N within 0.01 seconds. All the deformations, principle and shear stresses of the time response found in the vibrating golf head, shaft, grip and hand are compared with each other. Normal and eccentric impact analyses for HAGCM are examined as well. The angular velocity found in eccentric impact is much higher than that in normal impact, and it will cause the muscle to exert more power to hold the golf club.

In recent years, the processing technology of advanced machinery has toward precision, high-performance, and high-speed. Therefore micro-fabrication becomes more important such as the getting smaller aperture in the printed circuit board (PCB), it tends to be more severe due to vibration. The vibration has adverse effects to machining accuracy and surface roughness which will increase tool abrasion and further accelerate the destruction from material fatigue. There are many ways to produce perforations, such as laser micro-machining and micro-drilling. The industry still adopts micro drill piercing process due to the cost and technical considerations. In order to enhance the cutlery life and the quality of the drilling process, the cutting characteristic of bur is important. Hence, the vibration during drilling must be suppressed. This study is to investigate the dynamic analysis of a micro drill under ultrasonic vibration (50 kHz) excited with a piezoelectric-driven actuator experimentally and numerically by using finite element analysis. The results show that the vibration and the cutting forces are effectively reduced and thereby the cutting performance is improved when introduces ultrasonic vibrations during micro-drilling process.

There are different types of isolators which include rubber type, coil spring type, slide and rotating type and there are different types of dampers which include viscous type, oil type, and try friction type. Both isolators and dampers are common used to reduce vibration caused by forging or stamping process. However, a new way to reduce the vibration of the punch press is viscoelastic damping isolator (VDI) which can be widely used in manufacturing, electricity and gas supply, construction, transportation and warehousing, and other industries. This study analyzes a VDI composed by partitions, damping fluid, steel springs and level adjusters. Different numbers of the partitions are welded on upper and lower rectangular steel plates, respectively. Up to 150 tons of weight of the punching machines supported by steel springs which are placed at the edges between the square upper/lower plates. Screw types of level adjusters are placed between lower plate and thick steel base to tune the horizontal level of the isolator. High viscosity damping fluid is filled in the space between interlacing partitions around 60 % of the height of the VDI. Punching induced impact energy is dissipated by shear deformation between the damping fluid and partitions. This study uses 3D graphing software and finite element method (FEM) to investigate the dynamic characteristic of the damping isolator after impacted by the puncher. The normal mode analysis of the VDI is obtained. The isolator is settled within 0.3 seconds after 300.000 N of shock impact and satisfies industrial specification of large punchers with loading frequency of 100 cycles per min.

Fuel cell system is widely used in the mobile devices and USA space program. This project studies the feasibility of powering a small train with a hybrid fuel cell system by employing electric power integration technology. Specifically, this study performs the dynamic tests on a mini train powered by Proton Exchange Membrane Fuel Cell (PEMFC). The original 12 V, 100 AH lead-acid battery, which can provide 12 V, 0.5 Hp for the locomotive and carry 9~12 people, is replaced by a hybrid Proton Exchange Membrane Fuel Cell. After an oval railroad and a low-pressure metal hydrogen storage canister recharging station are built, the mini train is tested on weekend and holidays at the outdoor park of National Science and Technology Museum, Taiwan. The dynamic performance of the PEMFC system is analyzed and the feasibility of applying this system to mini trains is evaluated. After one year of running, the mini train has been operated over 1,200 hours and has been transported over 30,000 passengers. The hybrid PEMFC system works perfectly and meets the original goal. Results also indicate that the temperature significantly affects system performance.