V型槽對薄鋼板之動態挫曲特性之影響
Effects on dynamic buckling characteristic of thin plates stamped with V-grooves
Date Issued
2006
Date
2006
Author(s)
Chen, Jeng-Tang
DOI
zh-TW
Abstract
Firstly, experimental study was made for the dynamic buckling of thin plates stiffened by stamping with 1 to 3 parallel V-grooves in a clamped-end condition. The length of the blanks was set at the same value of 300 mm, while the width was of 70, 140 and 210 mm at a thickness of 1 mm, otherwise specified. The depth of V-grooves was set at values of 4, 7 and 10 mm. In both static and dynamic tests, the results show that the ability of the plates to resist buckling and to absorb deformation energy was substantially enhanced by stamping with V-grooves. Stamped with 1 or 2 grooves of smaller values in depth, the plates 210 mm wide had larger resistance to dynamic buckling than those of greater values in depth did. In general, increases in number and depth of grooves caused an increase in the plates’ capacity of energy absorption. However, the ability of the plates to resist buckling and to absorb deformation energy cannot be determined only in accordance with the second moment of area of cross section, because the plates sufficiently wide stamped with any number of grooves deformed plastically before buckled in dynamic tests and, the interaction between deep grooves during deformation also enhanced the capacity of energy absorption.
Secondly, by using the Taguchi method, this article studies the strongly influent parameters on buckling-resistant properties of thin steel plates stamped with V-grooves of various numbers and dimensions. The parameters include the distance between any two neighbouring V-grooves, the thickness of the plates, the number and the depth of the V-grooves. The Taguchi method with orthogonal arrays was used to determine the optimal combination of manufacturing parameters and reduce the variation in quality, but using a minimal number of experiments. The experimental results indicate that the depth of V-grooves, one of the four parameters of interest strongly influenced buckling properties under quasi-static loads. However, the thickness of the plates and the depth of grooves strongly affected the critical buckling loads and the capacity to absorb energy under high-speed impact loads. This investigation also demonstrates that the buckling-resistant properties of thin steel plates can be increased to reasonable required values by using a minimum number of trials in stamping various numbers and dimensions of V-grooves.
At last, this part numerically investigates the buckling loads and the absorbed energy of thin metallic plates stamped with V-grooves. By using the dynamic-explicit FEM Code, LS-DYNA together with the mass scaling technique and contact algorithm, the collapse processes of the plates subjected to various impact velocities were simulated. The results show that the buckling-resistant properties of plates stamped with V-grooves can be more than 12-times larger than those of plates without V-grooves. Also, the results from numerical modeling show good agreement with the experiments. Therefore, the suggested model and technique are helpful in the design of thin metallic plates requiring considerable buckling resistance.
Subjects
動態挫曲
V形槽
田口法
臨界負載
挫曲抵抗
Dynamic buckling
V-grooves
Taguchi method
Critical buckling loads
Buckling-resistant.
Type
thesis
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