| Summary: | 碩士 === 國立臺北科技大學 === 土木工程系土木與防災碩士班 === 105 === Taiwan has fragmented geology and complex structure naturally, frequent earthquakes, and hydrological conditions of seasonal rainfall and typhoons, so that the rockfall incident happened frequently. In addition, for small land and large population, the sudden rockfall incident resulted in constant disasters, endangering the nearby persons, vehicles and houses severely, it is the hardest challenge to geotechnical engineering. Therefore, it is necessary to improve the design implementation and inspection techniques for rockfall mechanism protection works.
Besides flexible textile work for watershed management in civil engineering, the rockfall termination protection engineering is mainly the buildings of open tunnel and rockfall shed. To study the rockfall failure mechanism and the energy dissipation system of open tunnel engineering, this study originates the Newtons Cradle behavior of physical experiment, and uses "contact" and "non-contact" physical quantities to study nondestructive testing technique. The acoustical (decibelmeter)-optical (double camera image analysis) system for non-contact measurement and accelerometer and impact force sensors for contact measurement are integrated to develop a multifunctional Newtons Cradle Apparatus.
The impact force or impact energy is applied to observe the dynamic deformation of test material, the energy dissipation characteristic of material can be obtained as design reference for rockfall protection.
This study builds the multifunctional Newtons Cradle Apparatus which can be adjusted according to the rockfall energy for the first time, according to the Newtons cradle theory of gravity potential energy variation transformation, the fitness is validated by reliability and validity authentication of dynamic shock energy dissipation. The standard test procedure and method can be combined with pendulum release altitude, rope length and weight to adjust the input energy (energy range: 0-1118J). The geometry and type of test member are selected, with contact measurement of acceleration, impact force sensors and non-contact acoustic measurement and high-speed photography image analysis, the dynamic feature of energy dissipation member under impact can be observed.
In addition, this multifunctional Newtons Cradle Apparatus can be used for dynamic impact, and it can be adjusted and extended to test dynamic bending moment, deflection, shear and tension as required in the future.
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