Experimental Study On The Flexible Joint Of Water Supply Pipeline Under Stretching And Bending

Urban water supply pipeline is an important part of urban lifeline engineering. It relatesto the normal operation of city. It play an important role in people’s production and living.Under seismic and geological disasters, underground pipeline are easily damaged, thisdamage can cause serious economic losses and secondary disasters, which become a seriousproblem that restrict urban sustainable development. Large amounts of data show that underseismic the destruction of the pipeline mainly is the interface. Our current specificationswhich is about seismic design of the flexible pipeline interface only considers the singleaxial tensile destructional form. At present most test of ductile iron pipe is concentrated inthe tensile, flexural and torsional experiment, but few people research under the tensilebending coupling experiment. So we do the experiment this time. The main work as thefollowing:1. There are summarized about the rubber band performance, including chemicalcomposition, mechanical properties, strength of pipe body, etc. Understand the characteristicsof the ductile iron pipe flexible interface, and the mechanical properties of rubber ring.Explain the importance of the pipeline rubber ring.2. Through study the DN80and DN100flexible interface of synthetic pipeline for thedifferent eccentric (e1=10mm, e2=20mm, e3=30mm and e4=40mm) making tensile bendingtest, we get the flexible interface of synthetic pipeline’s axial force axial displacement curveand bending moment corner curve under the action of stretch bending.3. The conclusion was drawn from the curve: the larger the eccentricity, the larger theaxial displacement of pipeline interface maximum axial force and the corresponding angle,the larger maximum bending moment and corresponding pipeline interface.4. According to the linear data fitting method of least square and using mathematicaltool box in MATLAB, it is concluded that the DN80and the DN100flexible interface ofsynthetic pipeline’s axial tension axial displacement and bending moment cornerrelationship of fitting curve and the fitting formula. The stiffness matrix for the flexible jointof pipe under bend-stretch is suggested.