Assessment of Stress-Displacement State of Cable Suspended Pipeline Bridge During Inspection Pig Motion

Author(s):  
Igor Orynyak ◽  
Igor Burak ◽  
Sergiy Okhrimchuk ◽  
Andrii Novikov ◽  
Andrii Pashchenko

Designing and maintenance of pipeline cable bridge with dynamic loads is complex because this problem belongs to the geometrically nonlinear problems. Analysis shown that existing mathematics models of cables have restrictions in use and we can’t use these cable models for dynamic loads calculations of cable-suspended pipeline bridge. Movement, produced by motion of inspection pig inside pipeline is an example of such dynamic loads. During its motion through the pipeline cable bridge the inspection pig induces additional stresses in pipeline due its weight and finite velocity which induces the vibration of the bridge. Its stress state assessment requires a lot of modeling, measuring and calculating actions to be done. First of all the initial static stress state of the cable bridge should be evaluated. It depends on the existing tension forces in the cable elements. They approximately were derived from the optical measurement of their geometrical curvatures with accounting for known weight density of the cables. Then, existing software tool for piping stress calculation “3D Pipe Master”, which operates by 12 degrees of freedom in pipe elements, was modernized to be able to take into account the geometrically nonlinear behavior of 6 d.o.f. cable elements. The equations which relate the elongations and rotations of cable elements with tension forces in cables are written in the form convenient for application of the transfer matrix method in the linearized iteration procedure which adjusts the measured displacements of the elements of the bridge with calculated one. In this way the initial tension forces in cables, in particular, and the bridge state, in general were determined. The dynamic part of the problem is solved by expansion in terms of natural frequencies eigenfunctions. Given inspection pig velocity calculation allows to determine the time dependence of generalized loads for each of natural vibration mode as product of the pig weight multiplied by mode shape displacement in point of pig position at the given time moment. Eventually the technique of Duhamel integral is used to calculate the dynamic behavior of the bridge for each natural mode of vibration. Two examples of dynamic stress calculation are considered. First is primitive one and relate to calculation joint interaction pipeline and cable system at dynamic loading. The second example concerns dynamic calculation pipeline cable bridge through the river Svicha during movement inspection pig. This bridge consists of two support, two parallel pipelines (1220×15) with bends and cable system. Analysis shown possibility uses “3D Pipe Master” software for the solving problems of durability pipeline cable bridge any complexity in the conditions of static and dynamic loading.

2019 ◽  
Vol 2 ◽  
pp. 61-70
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Oleksandr Gorobchenko ◽  
Serhii Turpak ◽  
Iryna Kyrychenko ◽  
...  

An increase in the volume of bulk cargo transportation through international transport corridors necessitates the commissioning of tank containers. Intermodalization of a tank container predetermines its load in various operating conditions depending on the type of vehicle on which it is carried: aviation, sea, air or rail. The analysis of the operating conditions of tank containers, as well as the regulatory documents governing their workload, led to the conclusion that the most dynamic loads acting on the supporting structures during transportation by rail. Namely, during the maneuvering collision of a wagon-platform, on which there are tank containers. In this case, it is stipulated that for a loaded tank container, the dynamic load is assumed to be 4g, and for an empty (for the purpose of checking the reinforcement) – 5g. It is important to note that when the tank container is underfilled with bulk cargo and taking into account movements of fittings relative to fittings, the maximum value of dynamic load can reach significantly larger values. Therefore, in order to ensure the strength of tank containers, an improvement of their structures has been proposed by introducing elastic-viscous bonds into the fittings. To determine the dynamic loading of the tank container, taking into account the improvement measures, mathematical models have been compiled, taking into account the presence of elastic, viscous and elastic-viscous bonds between the fittings, stops and fittings. It is established that the elastic bond does not fully compensate for the dynamic loads acting on the tank container. The results of mathematical modeling of dynamic loading, taking into account the presence of viscous and elastic-viscous coupling in the fittings, made it possible to conclude that the maximum accelerations per tank container do not exceed the normalized values. The determination of the dynamic loading of the tank container is also carried out by computer simulation using the finite element method. The calculation takes place in the software package CosmosWorks. The maximum values of accelerations are obtained, as well as their distribution fields relative to the supporting structure of the tank container. The developed models are verified by the Fisher criterion. The research will contribute to the creation of tank containers with improved technical, operational, as well as environmental characteristics and an increase in the efficiency of the liquid cargo transportation process through international transport corridors.


2015 ◽  
Vol 732 ◽  
pp. 223-226
Author(s):  
Martin Dub ◽  
Josef Kolář ◽  
František Lopot ◽  
Vojtěch Dynybyl ◽  
Ondřej Berka

During working of tram the chassis are dynamically loaded through acceleration, deceleration, passage curves and evidently by the roughness of the rail track. These added dynamic loads can significantly increase wearing of the chassis components and drive. In the case of tested tram problems with bearing housing into gear box occurred. Too rigid hinge bedding can cause additional parasitic load to bearings. It is desirable to investigate its stress state during acceleration, deceleration and other common drive regimes. For this purpose, strain gauges are used. Moreover, for the verification and better description of gearbox suspension behaviour, the Qualisys system for capturing and evaluating motion is used. Acquired data are processed in software Matlab and in user interface of the Qualisys software.


1985 ◽  
Vol 107 (3) ◽  
pp. 412-417
Author(s):  
Tae Hyong Chong ◽  
Aizoh Kubo

A method to apply the approximation formulae [1] for tooth fillet and root stresses of a thin-rimmed spur gear to the calculation of stress state of an internal spur gear is introduced, for the case of an internal spur gear which is fixed by bolts and/or supported by pinned coupling similar to geared coupling. By this method, reliable stress state at tooth fillet and root areas in the whole internal gear can be easily calculated.


2006 ◽  
Vol 324-325 ◽  
pp. 1059-1062
Author(s):  
Hyo Jin Kim ◽  
Sang Ho Lee ◽  
Moon Kyum Kim

An efficient and accurate numerical program with enhanced point collocation meshfree method is developed to simulate crack propagation under dynamic loading conditions. The enhanced meshfree method with point collocation formulation and derivative approximation in solids is presented. This study also presents the crack propagation criterion and computation of propagating direction, and the total structure of the numerical program named PCMDYC(Point Collocation Meshfree method for DYnamic Crack propagation). Several examples of crack propagation under dynamic loads are analyzed to simulate the arbitrary crack propagation under dynamic loads. The results show that PCMDYC predicts the propagating path of crack under dynamic loading conditions accurately and robustly.


2021 ◽  
Vol 11 (19) ◽  
pp. 8973
Author(s):  
Kun Zhong ◽  
Wusheng Zhao ◽  
Changkun Qin ◽  
Hou Gao ◽  
Weizhong Chen

Roof rocks in coal mines are subjected to the combination of in situ stresses and dynamic stresses induced by mining activities. Understanding the mechanical properties of roof rocks under static and dynamic loads at medium strain rates is of great significance to revealing the mechanism of rock bursts. In this study, we employ the digital image correlation (DIC) technique to investigate the energy concentration and dissipation behaviors, failure mode, and deformation characteristics of roof rocks under combined static and dynamic loads. Our results show that both the static pre-stress and dynamic loading rate have significant effects on the uniaxial compressive strength of rock specimens. From the energy principle, when the static pre-stress is the same, both elastic strain energy density and dissipated energy density increase with increasing dynamic loading rate. The hazard of rock bursts increases with decreasing static pre-stress and increasing dynamic loading rate. At higher dynamic loading rates, more cracks are generated, and the failure becomes more violent. The crack initiation, propagation and coalescence processes are identified, and the failure mode is closely related to the evolution of the global principal strain field of the rock specimens.


2022 ◽  
Vol 906 ◽  
pp. 7-15
Author(s):  
Dmitry Utkin

On the basis of theoretical and experimental studies, the prerequisites and the method of calculation of bent and compressed-curved reinforced concrete structures with zone reinforcement made of steel fiber, working under static and short-term dynamic loads, are formulated. In the developed method for calculating the strength of normal and inclined sections, a nonlinear deformation model is implemented, which is based on the actual deformation diagrams of materials. The developed calculation method is brought to the program of calculation of reinforced concrete structures with zone reinforcement of steel fiber under short-term dynamic loading, taking into account the inelastic properties of materials. The numerical studies made it possible to determine the influence of various parameters of steel-fiber reinforcement on the strength of reinforced concrete elements. To confirm the main results of the developed calculation method, experimental studies of reinforced concrete beam structures reinforced with conventional reinforcement and a zone steel-fiber layer are planned and carried out. Experimental studies were carried out under static and short-term dynamic loads. As a result of the conducted experiments, data were obtained that characterize the process of destruction, deformation and cracking of steel-reinforced concrete elements under such types of loading. The dependences of changes in the energy intensity of reinforced concrete structures with zone reinforcement made of steel fiber in the compressed and stretched cross-section zones under dynamic loading are obtained. The effectiveness of the use of fiber reinforcement of normal and inclined sections of bent and compressed-curved elements to improve the strength and deformative.


Author(s):  
V.G. Zotov ◽  
A.O. Nikitin ◽  
A.V. Yazykov

The paper presents the results of the analysis of the dynamic processes occurring at different stages of the operation of the installation unit of the super-heavy-class space rocket complex for one of the options for completing the Yenisei space rocket, intended for both the implementation of the lunar program and deep space exploration. Verticalization and installation of the ILV under consideration on the launch pad is carried out by a lifting and installation unit of an original design. The main feature of this unit is the presence of two tilting axes. The considered type of installation unit has not previously been used in domestic complexes for ILV. Despite some similarities of such a unit with a classic installer with lifting frame, in the course of its operation, specific operating modes arise with increased dynamic loading of the unit structure and the lifted product. The calculations made it possible to propose constructive solutions that ensure a decrease in dynamic loads on a space rocket during verticalization and installation on a launch pad.


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