起重機結構框架的優(yōu)化設計

　　摘要

　　為了找到能夠容易地安裝在常規(guī)農用車輛上以及從常規(guī)農用車輛移除的多用途起重裝置的最具成本效益的設計,在支撐裝置的主框架上執(zhí)行包括材料和制造費用兩者的成本優(yōu)化。優(yōu)化受到局部和全局屈曲和疲勞狀況的限制。將Snyman的基于梯度的LFOPC優(yōu)化算法應用于連續(xù)優(yōu)化問題,導致經濟地確定明確的連續(xù)解,然后將其用作離散可用輪廊集合內的鄰域搜索的起點,以獲得離散最佳。對于不同的鋼種以及與不同國家的制造和材料成本相關的最佳進一步調查。還研究了優(yōu)化目標函數(shù)的公式變化的影響。結果表明,通過優(yōu)化可以獲得相當大的成本效益,即在不同國家進行成本核算不一定導致相同的最具成本效益的設計,并且準確地表達目標函數(shù)(即現(xiàn)實的數(shù)學建模)對于獲得最大的收益預期的設計最佳。

　　Optimal design of a hoist structure frame

　　Abstract

　　In an attempt to find the most cost effective design of a multipurpose hoisting device that can be easily mounted on and removed from a regular farm vehicle, cost optimisation including both material and manufacturing expenditure, is performed on the main frame supporting the device. The optimisation is constrained by local and global buckling and fatigue conditions. Implementation of Snyman's gradientbased LFOPC optimisation algorithm to the continuous optimisation problem, results in the economic determination of an unambiguous continuous solution, which is then utilised as the starting point for a neighbourhood search within the discrete set of profiles available, to attain the discrete optimum. This optimum is further investigated for a different steel grade and for the manufacturing and material cost pertaining to different countries. The effect of variations in the formulation of the objective function for optimisation is also investigated. The results indicate that considerable cost benefits can be obtained by optimisation, that costing in different countries do not necessarily result in the same most cost effective design, and that accurate formulation of the objective function, i.e. realistic mathematical modelling, is of utmost importance in obtaining the intended design optimum. O 2003 Elsevier Inc. All rights reserved.