1、附录 英文原文 Calculation method and control value of static stiffness of tower crane Lanfeng Yu* Research Institute of Mechanical Engineering, Southwest JiaoTong University, Chengdu, Sichuan, 610031, P. R. China(Manuscript Received August 31, 2006； Revised November 30, 2007； Accepted December 13, 2007) A
2、bstract The static stiffness of tower cranes is studied by using the proposed formulations and finite element method in this paper. A reasonable control value based on theoretical calculation and finite element method is obtained and verified via collected field data. The results by finite element m
3、ethod are compared with the collected field data and that by the proposed formula. Corresponding to theoretical formulations and field data, it is found that the results by finite element method are closer to the real data. Keywords: Tower crane； Static stiffness； Control value； Static displacement
4、1. Introduction Sagirli, Bococlu and Omurlu (2003) realized the simulation of a rotary telescopic crane by utilizing an experimental actual system for geometrical and dynamical parameters 1. With the intention of comparing the real system and the model and of verifying the sufficiency of the model a
5、ccuracy, various scenarios were defined corresponding to different loading and operating conditions. Of the scenarios defined, impulse response, time response and static response are used to experimentally gather such system parameters and variables as damping coefficient, cylinder displacements, an
6、d stiffness of the telescopic boom, respectively. Following are the simulations for two dissimilar scenarios which are static response and impulse response and the results that were presented. Barrett and Hrudey (1996) performed a series of tests on a bridge crane to investigate how the peak dynamic
7、 response during hoisting is affected by the stiffness of the crane structure, the inertial properties of the crane structure, the stiffness of the cable-sling system, the payload mass, and the initial conditions for the hoisting operation 2. These factors were varied in the test program, and time h
8、istories were obtained for displacements, accelerations, cable tension, bridge bending moment, and end truck wheel reactions. Values for the dynamic ratio, defined as peak dynamic value over corresponding static value, are presented for displacements, bridge bending moment, and end truck wheel react
9、ions. A two degree of freedom analytical model is presented, and theoretical values for the dynamic ratio are calculated as a function of three dimensionless parameters that characterize the crane and payload system. Grierson (1991) considered the design under static loads whereby the members of the
10、 structure are automatically sized by using commercial steel sections in full conformance with design standard provisions for elastic strength/ stability and stiffness 3. This problem was illustrated for the least-weight design of a steel mill crane framework comprised of a variety of member types a
11、nd subject to a number of load effects. Huang et al (2005, 2006, 2007) analyzed the static and dynamic characteristics of mechanical and structural systems using fuzzy and neural network methods 4-11. For static stiffness of a tower crane, the requirements of GB 3811-1983 “Design rules for cranes” a
12、nd GB/T 13752-1992 “Design rules for tower cranes” of China are as follows. “Under the rated load, the horizontal static displacement of the tower crane body x at the connection place with the jib (or at the place of rotary column with the jib) should be no larger than H/100. In which H is the verti
13、cal distance of the tower body of the rail-mounted tower crane from the jib connection place to the rail surface, and the vertical distance from the jib connection place of the attached tower crane to the highest adhesion point”. In this paper a special research on the static stiffness of tower cranes was carried out aimed at relieving the over-strict control on the static stiffness ( x H/100) in the rules above, so as to meet the requirement for revising GB/T 3811-1983 “Design
