Study On Dynamic Response Of Cable-membrane Structure Under Impact Load

In our country,membrane structure has developed for several decades,which has been widely adopted in large-span space structures such as stadiums and terminals.It features beautiful form and exquisite structure,which contribute to the beauty of architecture and the combination of structure and architecture.Economically developed coastal area has more membrane structure architectures than inland area in our country.However,coastal cities often suffer from severe weather such as typhoons.Windborne debris caused by hurricanes can bring a huge damage to economy and society.Therefore,it is important for us to carry out research on the dynamic mechanical properties and energy dissipation mechanism of membrane structures under impact loads,which can improve theoretical reference in design and construction.In this paper,the Ferrari 1002T2 PVDF coated fabrics were used in research,which includes quasi-static tensile tests,impact tensile tests based on SHTB,impact loading tests of cable-membrane structure,accurate numerical simulation under the same working condition and so on.The main research contents and results are as follows:(1)The quasi-static tensile tests and impact tensile tests under different strain rates were carried out.The following parameters were considered in the tests including three quasi-static rates and five impact tensile strain rates,warp and weft directions.Two kinds of samples with the main axis along the warp and weft direction were tested respectively.The failure modes of specimens were discussed.The variation of coated fabrics’ mechanical parameters under different strain rates were obtained which including ultimate tensile strength,stress-strain relationship and the capacity of energy dissipation.The rate dependent mechanical properties of the material were fitted according to the test results.The results show that,with the strain rate increasing,more fibers are stripped and cracks increased when materials are damaged.The ultimate tensile strength and energy dissipation capacity are also rised.Under high strain rate,the mechanical properties of the materials are more sensitive.(2)The impact loading test is carried out by the typical cable-membrane structure as the research object.The dynamic response and energy dissipation mechanism of the cable-membrane structure under impact load were studied.In this paper,through the self-made membrane structure loading device and launching device,with the help of high-speed camera and laser displacement sensor,the whole process of membrane structure’s vibration under impact load was recorded and the displacement time-history curve and vibration were obtained.The following parameters are considered as studying in the tests including initial pretension,impact velocity,the impact position,the shape and size of the bullet.Then,it makes a comparative analysis that the laws of amplitude and vibration frequency under different working conditions.(3)The accurate finite element model of cable-membrane structure was established by adopting ABAQUS software.Based on the generalized Maxwell damping model,the rate dependent viscoelastic constitutive model was established by adding the rate dependent characteristic parameters of the material.In the paper,the effects of simulation results by using two different membrane element properties were compared and the better one is selected.The simulating results were compared with the experimental results to verify its accuracy.Based on tests,it made a parametric analysis of cables.And it is also studied the displacement,stress and energy of cable-membrane structure,which improved the research on dynamic mechanical properties and energy dissipation mechanism of cable membrane structure under impact load.There are 74 pictures,12 tables and 108 references in this paper.