Research On Mechanical Properties Of All Steel Corrugated Sandwich Pipes

The sandwich structure has light weight,high specific strength,and high specific stiffness,with small deformation under external forces,and has good stability and deformation resistance.Therefore,in engineering applications,sandwich structures are often used as load-bearing structures.For load-bearing structures,bending resistance and stability of compression bars are one of the most basic and important mechanical properties.These two properties directly affect the safety,reliability,and stability of the structure.It is very important to conduct in-depth research and exploration on the mechanical properties of sandwich structures.In recent years,sandwich tube composite structures with sandwich characteristics have received widespread attention.Its unique "sandwich effect" not only reduces pipeline weight,but also achieves better mechanical properties under the same material.Inspired by this,this paper designed and prepared an all steel corrugated sandwich pipe composed of outer pipe,inner pipe,and corrugated pipe.By exploring the influence of its mechanical properties and structural characteristics,the "sandwich effect" of this structural pipe was explored,aiming to provide a theoretical basis for the application of all steel corrugated sandwich pipe in load-bearing structures.Firstly,the three-point bending test and the finite element model of compression rod stability of all steel corrugated sandwich pipes were established by means of ASYNS finite element analysis software.Then,a kind of all-steel corrugated sandwich pipe with the same structural size was prepared by laser welding,and polyurethane foam sandwich pipe with the same inner and outer size was prepared.Three-point bending and stability tests were carried out on all-steel sandwich pipe,empty pipe and sandwich pipe respectively.Finally,the experimental and simulation results were compared to verify the accuracy of the simulation model and analyze the influence of structural characteristics(outer tube wall thickness,inner tube wall thickness,number of ripples and thickness of ripples)on its mechanical properties.The results show that:(1)The load-displacement curves of the test and simulation are in good agreement,which verifies the accuracy of the finite element model.The influences of the number of ripples,the thickness of ripples and the thickness of the inner and outer tubes on the mechanical properties of all steel corrugated sandwich pipes can be studied by changing the structural parameters of the model.(2)Compared with empty pipe and traditional sandwich pipe,the bending resistance and compressive resistance of all steel corrugated sandwich pipe are significantly improved.When the load reaches the maximum,all steel sandwich pipe continues to show very good bearing capacity.In terms of bending performance,the maximum bearing capacity of all steel corrugated sandwich pipe is 1.5 times and 2 times that of sandwich pipe and empty pipe,respectively.The bearing capacity of all steel corrugated sandwich pipe is 1.4 times and 1.6 times that of sandwich pipe and empty pipe,respectively.(3)The influence of the number of ripples on the sandwich pipe load displacement curve shows a nonlinear change.Origin software is used to get the load-displacement curve fitting equation and the corresponding parameter values when the three-point bending and compression rod are used,which provides a theoretical basis for the subsequent structural design and research of sandwich pipe.