scholarly journals Load calculation and strength analysis of floating garbage cleaning equipment

2021 ◽  
Vol 261 ◽  
pp. 03024
Author(s):  
Weiyao Xu ◽  
Jianting Guo ◽  
Chunyan Ji
Keyword(s):  
High Stress ◽  
Bending Moment ◽  
Strength Analysis ◽  
Floating Structure ◽  
Cleaning Equipment ◽  
Load Calculation ◽  
Calculation Results ◽  
Torque Load ◽  
Design Requirements ◽  
Vertical Bending Moment

In order to alleviate the problem that there is increasingly floating garbage pollution on the sea, this paper proposes a new design of floating garbage cleaning equipment. This equipment is a slender structure, and whether its structural strength can meet the design requirements requires special attention. In order to ensure the rationality and safety of the design, load calculation and strength analysis are carried out based on the design wave method. The calculation results show that the longitudinal torque load of this equipment is the largest, which is 2.5 times of the second largest vertical bending moment. At the same time, there are three large stress areas in the floating structure, which are the connection between the pontoon and the connecting buntons, the connecting buntons intersecting with the Y axis and the pontoons on both sides. For the abovementioned high-stress areas, a structural strengthening plan is proposed. After the improvement, the stress in the high-stress areas of the structure is significantly reduced, with a maximum reduction of 52%. The strength of the improved structure meets the design requirements. The research results of this paper can provide relevant references for the development of floating garbage cleaning equipment in the future.

Effect of Special Outermost Module Designs on the Hydrodynamic Responses of a Modular Multi-Purpose Floating Structure System

2019 ◽  
Author(s):  
Nianxin Ren ◽  
Chi Zhang ◽  
Allan Ross Magee ◽  
Xiao Liu ◽  
Øyvind Hellan ◽  
...  
Keyword(s):  
Bending Moment ◽  
Structural Deformation ◽  
Special Design ◽  
Floating Structure ◽  
Mechanical Coupling ◽  
Maximum Deformation ◽  
Heave Plate ◽  
The Time Domain ◽  
Extreme Responses ◽  
Vertical Bending Moment

Abstract The present work investigates the effect of different outermost module designs on the hydrodynamic responses of a modular multi-purpose floating structure (MMFS) system. The MMFS system is initially designed for a mild sea zone. As the entire system consists of more than 20 bodies, a simplified system with seven interconnected standardized modules is proposed for numerical and experimental study. In this simplified system, each module is assumed as a rigid body. Both hydrodynamic interactions and mechanical coupling among modules are taken into consideration in the time-domain numerical analysis. The structural deformation of the MMFS system mainly occurs in the connectors among adjacent modules. The maximum deformation appears at the connectors between outermost modules with the internal modules. To reduce the deformation and improve the concept, two special design, outermost module of deeper draft and outermost module with additional heave plate are proposed and investigated for the MMFS system. The numerical results indicate that the two proposed designs for the outermost module can significantly reduce the hydrodynamic responses of the MMFS system, especially the motion of the outermost module and the vertical bending moment on the connector. The extreme responses of the MMFS system with different outermost module designs are also studied and compared.

scholarly journals Strength analysis of capacitor energy storage cabinet of monorail elevated train

2022 ◽  
Vol 355 ◽  
pp. 02055
Author(s):  
Guojing Ye ◽  
Jinsong Zhou ◽  
Bingshao Li
Keyword(s):  
Energy Storage ◽  
Working Conditions ◽  
Equivalent Stress ◽  
Element Model ◽  
Strength Analysis ◽  
Static Calibration ◽  
Simulation Calculation ◽  
Maximum Equivalent Stress ◽  
Calculation Results ◽  
Design Requirements

Based on the actual parameters of the capacitor energy storage cabinet on the top of the monorail train, built the cabinet’s finite element model. Then, according to EN 12663-1, set the calibration conditions and fatigue working conditions. Carried out the simulation calculation under different conditions, respectively. The calculation results under the static calibration conditions show that the maximum equivalent stress of each node on the model is smaller than the allowable stress under all working conditions. Therefore, the static strength of the cabinet meets the design requirements. Plotted Goodman fatigue limit diagrams of the cabinet’s base metal and weld and modified them in the Smith form. Then plotted the average stress and stress amplitude under fatigue working conditions in the corresponding scatter diagram. The diagram s show that all points are located within the permitted area. The results show that the fatigue strength of the cabinet meets the requirements of design and use.

Design for Flexible Connector of Multi-Floating Structure

2020 ◽  
Author(s):  
Yuan Hongtao ◽  
Chen Gang ◽  
Zhang Wei ◽  
Yin Yan ◽  
Wang Yuhan ◽  
...  
Keyword(s):  
Structural Model ◽  
Structural Strength ◽  
Bending Moment ◽  
Calculation Model ◽  
Wave Direction ◽  
Regular Waves ◽  
Floating Structure ◽  
Hydrodynamic Calculation ◽  
Design Requirements ◽  
Element Theory

Abstract For the connector between the modules of a regular hexagonal multi-floating structure, it designed a flexible connector based on hinge joints and spin joints, which allowed part of rolling, pitching and torsion between adjacent modules to release bending moment and strain. A 221m multi-floating structure hydrodynamic calculation model was modeled in this paper. Firstly, the connector loads under the regular waves were calculated by ANSYS Aqwa. Secondly, structural model of a flexible connector was built by SolidWorks basing on the finite element theory. It analyzed structural strength of the flexible connectors under different load conditions of a series of wave direction angles by ANSYS Static Structral. Lastly, the results show that the design of the multi-floating structure connectors met the design requirements in different working conditions.

Short Term Statistics of Hydroelastic Loads of a Containership in Head and Oblique Seas

2018 ◽  
Author(s):  
Suresh Rajendran ◽  
C. Guedes Soares
Keyword(s):  
Frequency Response ◽  
Bending Moment ◽  
Structural Safety ◽  
Oblique Waves ◽  
High Frequency Response ◽  
Nonlinear Design ◽  
Load Calculation ◽  
Bow Flare ◽  
Large Container ◽  
Vertical Bending Moment

Vertical bending moment (VBM) is an important parameter for the structural safety of any sea going ship. Generally, it is expected that ships encounter largest VBM in head seas. However, when it comes to flexible ships, it is not necessary that the largest VBM always occurs in head sea. It can also occur in oblique waves and high frequency response in waves with shorter period can be as large as the wave frequency response or can be even larger. Studies conducted in the recent past by other researchers has shed some light into this peculiar characteristics of VBM of flexible hulls. Therefore, it will be worthwhile to further investigate to check whether the nonlinear design load calculation of the flexible hull in head seas will lead to conservative results or should be tested for a range of headings with different combinations of wave period in order to estimate the largest VBM acting on the hull. In this paper, the numerical and the measured VBM of an ultra large container ship (ULCS) in low to severe sea states are analyzed and compared. The effect of speed, significant wave height, springing and bow flare slamming on the response is studied. The measured VBM in head and oblique waves are compared and interesting findings are observed.

scholarly journals Stress and Strength Analysis of Non-Right Angle H-section Beam

2018 ◽  
Author(s):  
Mingyi Cai ◽  
Jianfei Yu ◽  
Xinmin Jiang
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Calculation Method ◽  
Shear Force ◽  
Bending Moment ◽  
Strength Analysis ◽  
Bending Stress ◽  
Design Requirements ◽  
Thin Walled ◽  
Object Of Study

In this paper, according to the design requirements of a steel structural project, based on the principle of structural mechanics of thin-walled bar, the non-right angle H-section, which is subjected to bending moment and shear force, is taken as the object of study, the formulas of bending normal stress and shear stress are deduced. On this basis, the distribution of bending stress and shear stress and the location of dangerous stress are analyzed, the calculation method of section strength is discussed, and the FEA software ABAQUS is used to verify the above. 

Post-Ultimate Strength Behavior of Very Large Floating Structure Subjected to Extreme Wave Loads

2012 ◽  
Author(s):  
Kazuhiro Iijima ◽  
Masahiko Fujikubo
Keyword(s):  
Ultimate Strength ◽  
Cross Section ◽  
Simple Formula ◽  
Bending Moment ◽  
Wave Loads ◽  
Extreme Wave ◽  
Floating Structure ◽  
Strength Behavior ◽  
Wave Induced ◽  
Vertical Bending Moment

In this paper, post-ultimate strength behavior of VLFS to extreme wave-induced loads is investigated. A mathematical model to describe the post-ultimate strength behavior of VLFS is developed taking the hydroelasticity into account. The whole VLFS is modeled by two beams on an elastic foundation connected via a nonliner rotational spring assuming that VLFS collapses amidship under severe bending moment. The model is solved numerically by using FEM. It is shown that the extent of collapse of VLFS is smaller than that of ship structures for given amplitude of vertical bending moment on condition that the structures have the same cross section and the same moment-displacement relationship. A simple formula to represent the extent of collapse of VLFS is derived. Its efficacy is shown.

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

Effect of Torsion on Collapse Bending Moment for 24-Inch Diameter Schedule 80 Pipes With Wall Thinning

2012 ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Bostjan Bezensek ◽  
Phuong Hoang
Keyword(s):  
Power Plants ◽  
Bending Moment ◽  
Combined Loading ◽  
Bending Moments ◽  
Compressive Stresses ◽  
Wall Thinning ◽  
Nominal Thickness ◽  
Calculation Results ◽  
Loading Modes ◽  
Local Wall Thinning

Piping items in power plants may experience combined bending and torsion moments during operation. Currently, there is a lack of guidance in the ASME B&PV Code Section XI for combined loading modes including pressure, torsion and bending. Finite element analyses were conducted for 24-inch diameter Schedule 80 pipes with local wall thinning subjected to tensile and compressive stresses. Plastic collapse bending moments were calculated under constant torsion moments. From the calculation results, it can be seen that collapse bending moment for pipes with local thinning subjected to tensile stress is smaller than that subjected to compressive stress. In addition, equivalent moment is defined as the root the sum of the squares of the torsion and bending moments. It is found that the equivalent moments can be approximated with the pure bending moments, when the wall thinning length is equal or less than 7.73R·t for the wall thinning depth of 75% of the nominal thickness, where R is the mean radius and t is the wall thickness of the pipe.

Tank Test and Numerical Simulation of Spar Type Floating OTEC

2021 ◽  
Author(s):  
Shunka C. Hirao ◽  
Jun Umeda ◽  
Kentaroh Kokubun ◽  
Toshifumi Fujiwara
Keyword(s):  
Numerical Simulations ◽  
Cold Water ◽  
Scaling Law ◽  
Internal Flow ◽  
Bending Moment ◽  
Floating Structure ◽  
Waves And Currents ◽  
Tank Test ◽  
Safety Assessments ◽  
Ocean Thermal Energy

Abstract National Maritime Research Institute, NMRI, had been studying the analytical method on safety assessments of floating power generation facilities for ten years more. As a part of these studies, an Ocean Thermal Energy Conversion (OTEC) was also studied in our institute. The OTEC normally has a very long and thick Cold-Water Pipe (CWP) with an unanchored end to pump up a large amount of cold-water continuously. From the viewpoints of the safety assessments of the OTEC operation, it is noteworthy to confirm the effect of the existing long pipe against a floating unit/body and an effect of internal flowing water. It is necessary, moreover, to consider the Vortex Induced Vibration (VIV) effect for floater motions and structural analysis of the pipe itself and a connecting point of the floating structure. In this paper, the results of model tests and numerical simulations of a spar type floating OTEC with a single CWP in waves and currents are presented. The CWP model was made of material fitting the scaling law for a planned full scale OTEC. The specific and unique phenomena of the floating OTEC were confirmed from the model test results. Based on the results of the tank tests and the numerical simulations, we confirmed the necessary items and arrangements for safety evaluations. In detail, the internal flow increased the bending moment at the connection point.

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