The Key Parameter Identification And Control Method Of Non-closed Hollow Fiber Airbag Damping And The Preliminary Investigation Of Solid Waste Spinning

It is an effective extension of the new damping material to spinning the viscoelastic materials into the hollow fiber,which adds the airbag damping to the damping of the raw materials and increases the total damping loss factor of the structure.However,for the non-closed airbag damping structure formed by walls with pore and fiber hollows,which is specially and innovatively designed by our team,its key parameters identification and control method have not been reported yet.In this paper,a new research result is described through experiments.First,the hollow fiber damping materials with different hollow inside diameters,different wall thicknesses,different wall porosity and different wall pore structure were prepared by adjusting and controlling the technological parameters and the formula of spinning casting solution of the hollow fiber spinning.It was found and confirmed that the size of the airbag(i.e.,the inner cavity determined by the inside diameter of the hollow fiber),the pore structure,the porosity and the wall thickness of the airbag wall were the most crucial parameters,which can affect the additional damping of the airbag in the hollow fiber.Meanwhile,the control method of the four key parameters influencing the airbag damping of the hollow fiber was also obtained.Finally,the validity of the damping control method of the airbag was verified,the mechanism and effect of the damping control of hollow fiber wall with airbag structure was proved.Then,some related parameters of other improved hollow fiber(lotus root airbag,core reinforced airbag)were also studied and analyzed.Finally,some wastes(iron tailing sand and aluminum ash)were used as part of casting solution to prepare hollow fibers,and a new approach for the resource utilization of the waste was initially explored.Comprehensively above,some useful rules and conclusions have been obtained:(1)The size of the airbag(i.e.,the inner cavity determined by the inside diameter of the hollow fiber),the pore structure,the porosity and the wall thickness are the most important parameters that affect the airbag damping of hollow fiber.Within the scope of the experiment,the wall porosity is the most significant parameter of airbag damping,and the damping peak value of structural damping can increases by about 40% with increases the porosity of the wall surface;The larger the inside diameter is,the higher the damping peak value is;The damping peak value of hollow fiber with 0.45 mm wall thickness is always larger than that of 0.35 mm hollow fiber damping material.It is helpful for damping dissipation when the wall pore structure has a thicker outer layer structure.(2)The hollow diameter and wall thickness of the hollow fiber can be effectively controlled by using spinning head with different inside diameters and corresponding spinning process parameters.The addition of pore-forming agents PEG and LiCl can effectively modulate the wall porosity and the wall pore structure of PVDF/PMMA hollow fiber,but there are optimal amount of addition respectively.(3)The airbag damping control mechanisms of hollow fiber are as follows: the increase of the wall porosity(the number of pore increases and the aperture decreases)and wall thickness can effectively increase the friction energy dissipation of gas vibration in the wall pore,which can obviously increase structural damping;Meanwhile,increasing the inside diameter of the hollow and the thickness of the external wall pore structure can effectively utilize the buffer energy dissipation of the gas in the airbag,so the structural damping can be increased.(4)In the range of experiments,for the hollow fiber damping materials in different lotus root airbag,the damping materials with one knot has better damping property;Hollow fiber damping materials with different cores have superior damping properties when they have a larger inner diameter,and the effective damping temperature range has also been widened,which have a certain significance for adjusting the airbag damping.(5)The hollow fiber damping materials can be successfully prepared by adding different amounts of the two types of aluminum ash as received into NBR/PVC casting solution.It is found that the peak value of damping loss factor of the material is still good,with only a slight decrease,and the effective damping temperature range is slightly widened.(6)The hollow fiber damping materials with better properties can be successfully prepared by adding different amounts of nano-aluminum ash and nano-iron tailing sand into NBR/PVC casting solution,and it is found that the peak damping loss factor increases in varying degrees.For nano-aluminum ash,in the case of high content,there is a greater impact on the material damping value;For nano-iron tailing sand,in the case of low content,there is a greater impact on the material damping value.(7)The core reinforced hollow fiber damping materials can be prepared by adding different amounts of nano-aluminum ash and nano-iron tailing sand into NBR/PVC casting solution and using a glass fiber braided inner core tube.There are two peaks in the inner core reinforced damping materials with different content.Although the damping peak value is greatly reduced,the damping temperature range is significantly widened.