Studying the distribution of a tower crane support loads using computer modeling

Abstract

Problem. The construction of modern industrial and civil structures is impossible to imagine without tower cranes. They are used in the construction of both low-rise and high-rise buildings and industrial structures. Tower cranes are simply irreplaceable in the construction of buildings, and in the construction of low-rise structures, these cranes have certain advantages over self-propelled jib cranes. Tower cranes are designed to mechanize construction and installation work, providing up to 98% of all lifting and handling operations during the installation of construction elements of buildings and structures, and are also widely used in various types of lifting operations. The advantages of tower cranes also include the optimal combination of virtually any vertical and horizontal lifting height to any point of the facility under construction. It is worth emphasizing the extremely large potential of the Ukrainian construction market and its need for a wide variety of tower crane models. Thus, tower cranes are one of the most popular types of equipment. Goal. The goal is to develop a methodology for determining the loads during operation on the supporting elements of a tower crane with a support circuit, taking into account the spatial nature of the load and identifying patterns of change in the distribution of loads on the supports during crane operation. In this work, the tasks are achieved by applying an advanced calculation methodology with the use of computer modeling tools that allow the use of labor-intensive calculation methods that take into account many factors.
 Methodology. The main objective of the work is to develop a methodology for determining the loads during operation on the supporting elements of a tower crane with a solid support contour, taking into account the spatial nature of the load and identifying patterns of change in the distribution of loads on the supports during crane operation. 
 Results. It was found that the load of the crane support elements is oscillatory with an amplitude of about 200 kN. When the crane boom is rotated by 135 degrees, support 4 can withstand the greatest load, which is 250 kN, and support 2 is almost unloaded – 5 kN. At a turn of β = 225 degrees, a similar situation occurs with supports 1 and 3, respectively. When the overhang changes, supports 1 and 4 can withstand the same loads in the range of 68 to 190 kN, and supports 2 and 3 can withstand loads from 190 to 50 kN. At the maximum outreach, the critical positions of the crane are when the boom angles are β=45 degrees and β=315 degrees, in which case the crane rests on almost three supports. Originality. This task is achieved by applying an advanced calculation methodology with the use of computer modeling tools that allow the use of labor-intensive calculation methods which take into account many factors. Practical value. Using the developed algorithm for calculating the loads on the crane supports, a computational experiment was conducted to determine the magnitude and nature of changes in the loads on the crane supports under different operating conditions: with different loads and variable outreaches, wind loads.