Study On Mechanical Property Of Polyurethane Filled Double Skin Steel Tubular Members

With the development of materials, as a new kind of high-performance material,steelpolyurethane composite material with its superior mechanical properties is widely usedin marine engineering, ocean engineering and civil engineering. A new form of compositetube has been presented in this paper based on the materials, which is filled polyurethanebetween the concentric inner and outer steel tubes to form a new composite member—polyurethane filled double skin steel tubular member (PFDSST member). Based onexperimental study and finite element numerical simulation method and so on, thecomposite tube has been researched roundly. The specific work has been done as follow:(1)Deformation characteristics and failure patterns of the PFDSST specimens havebeen researched with emphasis by experimental studies; with the studies and analysis ofexperimental results, the influence laws of hoop coefficient and slenderness ratio onPFDSST members have been gotten, the mechanical properties and working mechanismshave been known well; on the basis of existing calculation formulas of CFST members, thecomputational formulas for ultimate loading capacity are presented by the amendment onexperimental results.(2)Based on material tests of steel and polyurethane and the experiment of eachPFDSST member, the mechanical property of each PFDSST member under axialcompression has been studied by nonlinear finite element software—ANSYS. Thenumerical simulation results are in agreement with the experimental results, so thecorrectness of the finite element numerical simulation method has been validated, which issuitable for the analysis of the structure.(3)The mechanical properties of PFDSST members under axial compression have beenstudied by roundly based on the former research results, and critical slenderness ratio hasbeen introduced, the influence laws of hoop coefficient and slenderness ratio on PFDSSTmembers, the mechanical properties and working mechanisms have been gotten andanalysis deeply. And the numerical simulation results are in agreement with the resultswhich are gotten by simplified computational formulas for ultimate loading capacity ofPFDSST members.(4) The PFDSST members under axial tension and PFDSST members under pure twisting load has been studied by nonlinear finite element software—ANSYS, the influencelaws of hoop coefficient and slenderness ratio on tensile property and torsion property ofPFDSST members have been gotten and analysis; mechanical properties and workingmechanisms of PFDSST members under axial tension and PFDSST members have beengotten; on the basis of existing calculation formulas of CFST members, the simplifiedcomputational formulas for ultimate loading capacity of tensile members and torsionmembers are presented by the regressive analysis on the results.The basis of theories and experiments which is the use of PFDSST in oceanengineering and civil engineering is established by the research results of this paper, theseresults have good practical value and directive function in engineering practice.