Papers by Keyword: Shell

Abstract: There is a general condition of the stress created by superficial forces in praxis. It can be also simplified when the shifting the forces and bending torques are equal to zero, or we can ignore them because they are too low. In term of draft it is just a condition which has the best result when the material for the construction is exploited. The edge of the cylindrical container failures are the differential base for the axisymmetric shell within an internal pressure. That main point of that contribution is the effect of the internal load and the bending effects to joining pressure of the slice cylindrical part and the plate bottom.

Abstract: In conventional charge structure, the shell of charge’s containment is normally closed, with no explosive. When initiating charge, shell expanding to the outward, rupturing and eventually spreading out which was driven by the charge, this don’ have a guiding role to the detonation product flow. To further enhance the control of charge’s detonation product and energy flow, realizing the effective use of detonation products. The thesis put forward a structure design of filling thin-layer explosive in multi-layer shell, by initiating thin-layer explosive to control the deformation of shell, obtaining a approximately function with Laval Nozzle structure which can control the gas product when charge detonation. The thesis put forward a structure that including multi-layer explosive shell, establishing a numerical simulation model. Analysis the difference of shell’ deformation on different initiation method, provides a design references for further engineering application.

Abstract: During the application of approximated methods of estimations for calculating a stress-strain state of the shell an explicit question of accuracy and resource-intensiveness of the method is raised. From that point of view, the method of subsequent parameters perturbation (MSPP), developed by Vladlen V. Petrov in 1975, can be called the most effective one. The result of the application of this method is that the solution of a nonlinear model can be reduced to the sequence of solutions of systems of linear equations. The application of the method of Bubnov-Galerkin for solving linear equations is conjugated with the necessity of building the basis system of functions for every concerned problem. The method of building the basis system of functions for the shell with the boundaries of arbitrary configuration is offered in this paper..

Abstract: Modern architecture is dominated by the tendency to design organically shaped filigree buildings. The resource and energy efficient construction of multifunctional buildings is as important as a broad variety of possible shapes. Multi-material support structures and shell constructions in lightweight design that also take over e. g. lighting and monitoring are needed for these purposes. Textile reinforced lightweight shell structures have been developed at Technische Universität Chemnitz within the scope of research projects. They consist of a hybrid material from carbon-fiber-reinforced concrete and glass-fiber-reinforced plastic. Thanks to the coupling of the positive material characteristics, the combination of two different composite materials results in a hybrid material with a total thickness of 15 mm, which has a high fatigue strength (XF4) and surface quality (exposed concrete). Furthermore, the hybrid is characterized by excellent compressive strength (120 MPa) and bending tensile strength (150 MPa), low susceptibility to corrosion and free formability. Therefore, it is highly suitable for thin-walled filigree lightweight shell structures. A research pavilion with a size of 4 x 4 x 3 m3 (l x w x h), made from textile reinforced lightweight shells, was built on the campus of TU Chemnitz, to test the theoretical investigations. Specially developed tensile sensors for the active lighting and determination of the elongations were integrated into the different layers. This aimed at an online-monitoring of the shell support structure.

Abstract: The paper discusses the problems on accurate assembly of large-sized cylinder segments by illustrating an example of the geokhod assembly. The mathematical expressions for determining deviations of sector profile from the nominal circle of the shell depending on the radius of sector, its tolerances and the location of supports. The influence of the distance between the supports on the profile deviation is shown. Solutions to minimize the profile deviation are given.

Abstract: The strain-stress state of the solid propellant rocket engines (SPRE) is simulated under impact. Orthotropic organoplastic is the material of the shell. The effect of orientation of elastic and strength properties of the shell material on the strain-stress state of the solid propellant is investigated. Normal interaction of single steel cylinder strikers and oblique impact, both simultaneous and at different times of multiple, converging steel spheric particles with SPRE are considered in the work. The investigation is conducted numerically. The numerical modeling was carried out in three-dimensional statement by a method of finite elements in frameworks of the continual approach of the mechanics of deformable solid. The destruction of the anisotropic material is described by tensor polynomial criterion of the fourth degree, which takes into account the influence of hydrostatic pressure.

Abstract: Recently, variousresearches and developments of heat exchangers with high thermal efficiencyhave been in progress to save energy. Baffles are used as design variables in a way that enhancesheat transfer performance of shell and tube heat exchanger. There have beenvarious of researches and developments in the relations between baffles andheat transfer performance. Existing studies on shell and tube heat exchangersare mainly about heat transfer properties of either segmental type baffles orhelical baffles. However, there is inadequateof study with comparisons between the two types ofbaffles. Thus, this paper aims to research changes in heat transfer properties according to thenumber of segmental and helical baffles. It shows pressure drop, temperaturedifference of inlet and outlet, heating surface area of inner flow region, andheat transfer coefficient in tubes.

Abstract: Heat losses through the shell of rotary furnace represent a significant share of total energy expenditure for the heat treatment processes of raw materials. Heat loss is currently not used in any way and escapes into the surroundings. Controlled cooling system of rotary furnace shell is a new solution integrated into the technological process aimed at reducing heat losses by the shell of furnace. The proposed solution is economically advantageous and operationally undemanding.

Abstract: Crystal Eco-brick is a new ecological generality of decoration material. The shell is a key component of indoor stereo virescence concept combined with interior decoration materials. After crystal Eco-brick shell design had been finished, related technology research as well as development for the first, the second and third generations productions were done. The third generation of Crystal Eco-brick shell reached excellent characters such as strong universality, simple operation, high strength, more suitable for indoor afforestation.

Abstract: In the paper steadiness of the compressed and twisted drill rod is examined. The rod is presented in the form of a circular cylindrical shell, which is circulated from the outer side by a supersonic stream of gas. The rod is affected by the uniformly distributed on its length axial force and the torque. The problem of stability is solved by means of reviewing of a small deviation from the periodic solution of the problem. Boundaries of instability zones of the mechanical system are defined with application of the method of harmonic balance.