Mechanics Calculation of FRP Tube and Research on Axial Compression Member of Concrete-filled FRP Tube
|School||Huazhong University of Science and Technology|
|Course||Bridge and Tunnel Engineering|
|Keywords||FRP tube Concrete-filled FRP tube Axial compression Stress-strain relationship FRP laminate plane Stiffness and strength Axis pressure bearing capacity|
Fiber Reinforced Polymer (short for FRP) receives increasing concern in the field ofcivil engineering and composite materials, because of its advantages such as light weight,high tensile strength, corrosion resistance, anti-fatigue and designability. Concrete-filledFRP tube which is produced by pouring concrete into the FRP tube has a wider applicationthan concrete-filled steel tube as concrete-filled FRP tube combines the excellentcompression capability of concrete and the outstanding advantages of FRP this newmaterial.Currently, most of the trials are on the topic that the thickness of FRP tube, fiberwinding angle and fiber type affects the axial compression performance of concrete-filledFRP tubes. Those trials don’t have a fundamental study on how these parameters impactthe mechanical properties of FRP tube and then affect the axial compression performanceof concrete-filled FRP tubes.This paper first introduces the mechanical properties of the fiber and matrix whichare the component materials of FRP, winding process and pultrusion-winding forming ofmanufacturing FRP tube. Then the paper establishes the stress-strain relationship andstrength theory of the FRP unidirectional plate which is the basic unit of FRP tube, statethat the FRP tube (i.e. FRP laminate plane) is formed by several FRP unidirectional platesby different laid angles, laid sequence and laid thickness, infers the constitutive relation ofFRP laminate plane, calculates axial elastic modulus, axial poisson’s ratio andcircumferential elastic modulus, circumferential poisson’s ratio, analyses the failuremechanism of FRP tube, puts forward the calculation method of the strength of FRP tube.With the mechanical parameters of FRP tube calculated with the mothed discussed above,the paper develops the calculation method of axial compression stress-strain curve and afew damage limit mechanical parameters of concrete-filled FRP tube after the axialcompression stress analysis and mechanical calculation of concrete-filled FRP tube. Onthe basis of calculation theory of FRP tube, the paper sums up the calculation frameworkthat is from the type of fiber and matrix, winding style of FRP unidirectional plate tostiffness and strength of FRP tube and axial compression stress-strain relationship and ultimate bearing capacity of concrete-filled FRP tube. At last, the paper designes severaltrials to determine the elastic constants and circumferential fracture strain of FRP tube,axial compression stress-strain relationship and ultimate bearing capacity ofconcrete-filled FRP tube.