Mechanics Property Analysis And Optimization Design Of The Steel Framed Reinforced Composite Plastic Pipes

Currently, the market demand of steel-framed reinforced composite plastic pipes iscontinuously increasing; meanwhile, the requirements of the pipes working performance areconstantly improving as well. Therefore, more researches should go deep into the problems ofpipe’s mechanics property analysis and optimization design, which can provide theoreticalguidance for solving practical problems. Thus, this aspect of research has been attached withgreat importance since it is not only related to the using safety of pipeline systems, but also has adirect impact on the production cost.The thesis employs finite element method and finite element analysis software ANSYS toconduct the numerical simulation of two kinds of structural steel framed reinforced compositeplastic pipes, and construct the corresponding mathematical and finite element models. Indifferent conditions, the specific mechanics property of the pipes and the structure optimizationaldesign of the pipes are completely analyzed. The main contributions of the research are asfollows:First of all, the research on mechanical properties (strength, deformation, failure mechanismetc.) of composite pipe or tubular structure made of composite material has been reviewed. Then,the structure characteristics and performances of steel-framed reinforced plastic composite pipeare analyzed.Moreover, the distributions of stress and strain of steel-framed reinforced composite plasticpipes are studied under the internal pressure condition and water-hammer pressure conditionrespectively, and the impact of different pipe parameters and constraints on the calculationresults was summarized. From the results comparation of the theoretical analysis with numericalcalculation, we can draw the conclusion that finite element is a great method to accurately anddirectly predict the stress deformation of composite pipe, and to construct the parametric finiteelement model for composite pipe reasonably and efficiently.Furthermore, the influence of temperature on the mechanical properties of the steel-framedreinforced composite plastic pipes is analyzed, and the heat-stress analysis of the composite pipe is completed by utilizing the indirect method in ANSYS software The temperature fielddistribution of pipes under different temperature conditions is then acquired. In the view ofdeformation situation and thermal elongation of free expansion the coefficient of linearexpansion is calculated accordingly.Finally, the structural optimization of steel-framed reinforced composite pipes is achievedusing ANSYS parametric design language (APDL). The parametric optimization design iscompleted on the premise of taking the abstractedly characteristic parameters as design variables,taking the maximum deformation and maximal effect force as state variables, and takingminimum volume as target function. Thus, the optimization results can provide the theoreticalbasis and design reference for the development of new type of pipes.The research results show that, steel-framed reinforced composite pipes, which retain theadvantages of plastic and metal simutaneously, have great mechanical properties. CAE theoryand technology should be widely employed in the analysis and design process of compositepipes for simulating actual deformation situation, since the analytical results can be used not onlyas an important reference, but also as guidance for the design and development of new type ofpipes, which will increase the maximum utilization of the material and make pipeline morecompetitive in the market.