Plastic Hydraulic Device Structure Analysis And Design Improvement Research

The hydraulic device is a general name of the same matched category,including underground pipelines and storing water system. Such as sanitary sewer manhole,septic tanks,power check well,biogas digester and so on.The traditional hydraulic device is generally formed by brick or reinforced concrete.There are always some problems during the use,such as leakage and shorter lifespans,because that the mortar is often not solid when it is built.As the development of plastics industry,underground plastic pipelines are widely used in the fields of municipal and construction.Because the materials of traditional hydraulic device and plastic pipeline are different,the transformation is inharmonious,and thus make the phenomenon of the leakage in the jointing point outstanding.To solve these problems and meet the requirement of sustainable development and energy saving,it is necessary to develop new plastic hydraulic devices.The traditional designed method of plastic hydraulic pipeline is to calculate or check the strengthen and rigidity of structure by the theory of classic mechanics.Because the result calculated by formula always have large errors,especially in the high stress area,it is hard to calculate accurately for the actual structure.And the design only works by experience,which will result in the lack of local strength or excessive safety margin and so on. With the development of computer technology and finite element theory,it makes it possible to research the structure of the hydraulic device by modern design methods. To research the structure of these plastic check well,this passage designs the structure of injection mold for plastic device,taking a kind of plastic check well as the research object.By considering the nonlinear plastic material of inspection wells, this paper calculate the nonlinear numerical simulation.On the basis of modifying the model of finite element combined with the experimental test results,it analyze the structure of plastic inspection well.The main contents of the research are as follows:1、Understand the basic ideas of the finite element method. By using finite element analysis software, this paper set up two kinds of simplified models of plastic inspection well.Through the numerical simulation of filling process of inspection well, the author obtain the stress field and the displacement field of the inspection well’s structure in different depth of backfill. And this paper compare the calculation of floor enhanced plastic check well and flat wall type check well.2、By using electrometric method,making the actual underground test for plastic inspection well,it can obtain each point’s stress values in different depth of backfill and structural stress measurement point’s variation curve in different working conditions.Then this paper modify the finite element model by comparing the calculations of finite elements.3、By analyzing the structure of plastic check well, the author learn the technology requirements of the injection mold,and complete the selection of plastic injection molding machine of inspection wells.Then the author design the structure of plastic mold check well on that basis.4、By calculating and analyzing the different designed height of inspection well rib, the author research the rid plate’s effect on the mechanical properties of the plastic inspection well structure.5、This paper research the structure and force situation of inspection well according to the different soil and different ingredients of materials. 6、By making integral structure models of soil and inspection well, this paper research the soil’s effect on the structure.Then the author analyze the structure’s actual mechanical behavior by comparing the calculations of traditional soil mechanics formula.7、On the basis of the research in the plastic inspection well, the author make a introduce and the finite element analysis with other plastic hydraulic structures, such as plastic septic tanks and plastic aqueduct.