| Co-Investigator(Kenkyū-buntansha) |
KITOH Hiroaki Osaka City University, Faculty of Engineering, Department of Civil Engineering,, 工学部, 助手 (40177879)
SONODA Keiichiro Osaka City University, Faculty of Engineering, Department of Civil Engineering,, 工学部, 教授 (70047108)
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| Research Abstract |
(1)The propagation of elastic stress waves in sandwich type plated structures such as sandwich beams, ciecular plates, hollow cylinders and shperes, is investigated. Based on the theory of elastodynamics the method of eigenfunction expansion has benn developed to obtain exact solutions for these elastic impact response problems. Numerical calculations are performed for the various sandwich type sutrctures, especially, stee-concrete composit ones, and stresses variations at transient states and long time states are obtained. A comparison between the maximum dynamic stress and the corresponding static stress shows that the dynamic factor is 2 for beams and plates, but for hollow cylinders and shperes the dynamic factor to be low in varying degree depending on the particular loading condition, view points of stress, etc.
(2)Considering non-linear behabiour, numerical analysis of impact fracture of reinforced concrete rock sheds are made usig Rigid Body Spring Model. A number of numerical simulations are executed under various loading conditions such as weights of rock-mass, rock fall-heights, collisions angles of rock-fall and so on. Two types of faliure mode are observed, one is bending failure mode and the other is shear failure mode due to diagonal cracks of concrete. From the numerical results obtained, the difference between the statical and the impact characteristics of the rock sheds are revealed.
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