A Design Method for Fatigue Life of High-rise Towers for Wind and Vibration Resistance

Abstract

The invention belongs to the field of structural design and safety assessment of high towers and particularly relates to a method for designing fatigue life of a windproof and shockproof high tower. The method specifically comprises the following steps: setting reference wind speed and determining a discrete wind speed and direction joint probability distribution interval; designing various structural forms of dangerous section parts and solving stress concentration factors thereof; simulating a nominal stress time-history response of a dangerous section of the high tower in different directions at each reference wind speed in unit time; calculating the wind-induced fatigue life of the high tower with the dangerous section part in different structural forms and at different defect assessment levels; judging whether the life meets a requirement or not, determining a design scheme if the requirement is met, redesigning the overall structure of the high tower if the requirement is not met and performing the processes again. The method provided by the invention can provide a reference for the reasonable design and the safe operation of the high towers in coastal windy areas.

Description

technical field [0001] The invention belongs to the field of structural design and safety assessment of high-rise towers, and in particular relates to a fatigue life design method for high-rise towers used for windproof and anti-vibration. technical background [0002] Tower is one of the most important unit operation equipment in the production of chemical industry, petrochemical industry and oil refining, etc. Its performance has a great influence on the production capacity of the whole device, three waste treatment and environmental protection. Wind load is one of the more sensitive loads on the tower. It can cause the tower to vibrate in the downwind direction along the wind direction and in the cross-wind direction perpendicular to the wind direction. Too frequent down-wind or cross-wind vibration may cause its structural fatigue cracking or even fatigue failure. For large vertical towers, such as demethanizers, rectification towers, and coke towers, although the influ...

AI Technical Summary

Problems solved by technology

For large vertical towers, such as demethanizers, rectification towers, and coke towers, although the influence of wind loads has been considered in traditional designs, wind-induced fatigue may occur in towering structures in windy environments such as coastal areas Inadequate consideration of the potential hazards of

When some high-rise towers have local high stress concentration areas due to unreasonable structural design in actual use, or there are congenital defects in their manufacture, or various new defects generated under the long-term action of corrosive media, these will make The load-carrying capacity of the high-rise tower is greatly reduced, which makes the high-rise tower produce fatigue cracks under the long-term wind-induced vibration, which eventually leads to cracking of the tower, leakage of flammable, explosive or toxic and harmful gases, and brings safety hazards to the production of enterprises In recent years, the accidents caused by towering towers have also caused relatively large economic losses to related companies.

[0003] However, current domestic and foreign standards and regulations, such as the American Society of Civil Engineers (ASCE) standard, my country's construction industry's GB50135 "Code for Design of Towering Structures" and the pressure vessel design standard JB / T4710 "Steel Tower Vessels", although they all The wind load and wind vibration response of the structure have given a clear calculation method, but these methods regard the wind load as a short-term load, and have not considered the fatigue problem of tall towers in a windy environment, and this kind of load equivalent to the wind direction The traditional method of static load and only considering the critical resonance response in the cross-wind direction is not suitable for the fatigue life design of tall towers

At the same time, the wind speed and wind direction in the area where the tower is located has a certain distribution law, which will undoubtedly affect the wind-induced fatigue life of the tower, and with the increase of the height of the tower and the use of high-strength materials, the wind sensitivity problem is also more prominent

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