Research On Lateral Impact Response Of Fully Clamped Tubular Structures

Tubular members are widely used as the basic component in offshore jacket and jack-up platforms.Such structures are often exposed to the risk of ship collisions and dropped objects.Once the tubular member is damaged by collision accident,potential consequences may vary from minor local structural deformation to major threats to structural integrity.In extreme conditions,the damage of tubes may cause the global collapse of entire structures,which can lead to great economic loss,severe environmental pollution and put human lives in jeopardy.Therefore,conducting a research on the lateral impact response of tubular members and giving the rule of deformation damage and force response of tubular members after collision can help researchers have a fundamental understanding of the deformation mechanics of laterally loaded tubes so that tubular structures can be designed accordingly to have sufficient strength to withstand the lateral impact loads.In this paper,a series of researches have been carried out on the impact response of fully clamped tubular structures under lateral quasi-static loads by means of tests,numerical simulations and simplified analytical methods,the main contents are as follows:Firstly,the experiment of fully clamped tubular structures under lateral quasi-static impact loads were conducted to discuss the influence of among different impact factors such as the diameter and thickness of the tubular structures are respectively 159 mm×5 mm and 114mm×8mm,the length are 1200 mm,1500 mm,1800 mm and 2500 mm,the impact of wedge indenter and rectangular indenter,the middle and quarter collision position on the impact response of tubular structures with fully clamped under lateral quasi-static loads.Secondly,according to the true stress-strain curve of the material and the critical failure strain under the specified element size which are acquired from the result of uniaxial tensile test and numerical simulation analysis of the tensile specimen,the impact response of tubular structures with fully clamped under lateral quasi-static loads were analyzed by numerical simulation method.The simulation results are compared with the experimental results,a good identity of results have been reached.Then,based on the experiment,the influence of different size of tubular structure,different width of indenters and different collision positions on the impact response of the fully clamped tubular structures under lateral quasi-static loads were further discussed by setting up more groups of compared numerical simulation analysis.Finally,combined the research results of Wierzbicki and Yu,and on the basis of the results of experiments and numerical simulations in this paper,an improved simplified analytical method was proposed to analyze the force response of the fully clamped tubular structures under lateral impact loads by using the principle of virtual work.By comparing with the experimental results,the improved simplified analytical method can reasonably predict the force response of the fully clamped tubular structure under lateral impact loads.