 Wysłany: Wto 12:17, 29 Mar 2011 Temat postu: Lin loading bridge design load value of _137 |
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| Lin loading value of the bridge design load
To eliminate resonance. In more than one degree of freedom free vibration of multiple degrees of freedom system, the amplitude of the vibration body A1, A, ... can not be obtained, but can find the amplitude of the oscillation frequency than seven l + Af m} July 2 for a lai - a cutting: = lA Lan Zhu 2 = 1.8 = 0.55 amplitude ratio reflects the ratio of two vibration systems with different frequencies rio body and m2 forms of fundamental vibration vibration, called the first and two main modes. Free vibration of two degrees of freedom is obvious particular solution for the two combinations. 1 = A ~, sin (∞ J + port) + A ~: sin (2 £ + Shan port) X1: A ~, sin (eo2t + port) + A ~: sin (Shan 2 £ + port) Generally speaking, each harmonic vibration of a vibrating body is not, but the combination of different frequency harmonic vibration. Shi e (d-mm 【's 2zz sitting justice on the occasion of the 0 = h0 A = _ + 2 (x + 2 Liudao Yun et al: Design of forestry crane load value of 97.1 .2 design load (maximum load) to determine the analysis of the main beam, trolley, cable and cargo system, the main beam as the elastic body, the formation of free vibration of two degrees of freedom, the impact on smaller cables and goods, but in considering the most unfavorable situation, the main beam can be seen as a rigid body. At this point the goods to be slowed down, and suddenly brake, resulting in a role in the main beam of the maximum dynamic load. If you are still using copper cable elasticity coefficient 2 = 40kN/cm, goods mass M = 8000kg (W3 = 80kN), then the natural frequency of vibration system = li = 22.36 (rad / s); elastic static elongation. = w/k2 = 2.0cm; system of amplitude A = / i (t = 0,scarpe nike 2011,0 = 0); cable maximum tension d = d · k2; cable total elongation = d + A. When the goods the rate of decline V0 = 015 ~ 2.0m / s to calculate the corresponding amplitude when A, the total elongation, tension T and the dynamic load factor N. them are listed in Table 1. Table 1 Power f Department of deposited charge】 calculated Tab1ReckonerOrdynam ~ ~ oeffioiertt be seen from Table l, when the rate of decline in Vo increases its power coefficient doubled increase, it must be strictly controlled in the operation rate of decline in the goods after the conclusion of two terms, the maximum load and the rate of decline of goods V. related decline in goods it produces the braking moment. When the rate of decline in the goods when the power factor V0 = 05 N = 2.13iV0 = 10 时 N = 3.24; V0 = 15 时 N = 4.35; V0 = 2.0 when N = 545 ... .... l can be seen from the table, citing a power factor greater than Dynamic coefficient of recommended textbooks. Therefore, the use of the existing crane, the rate of decline must be strictly controlled, strictly prohibited in the v.> 0.5 (m / s) in the case of braking, and to the loading bridge to make clearly defined operating procedures (materials not made in the provisions of the rate of decline) trying to change the material presented in this study, the maximum load (design load) of goods produced in the initial moments from the ground to enhance the conclusions, because it does not meet the principles of mechanics . OntheDesignLoadValueofForestryStevedoringBridgeLiuDaoyunYangRenXuGuixiang (ForestryEngineeringDepartmentofJilinForestryUniversity, Jilin, 132013) AbstractThebasoftreditionaldeignloadwasquestioned |
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