Development of High Energy Absorbing Seismic Tie With I-Sectional Shape for Thermal Power Boiler Structure

2013 ◽  
Author(s):  
Kiyoshi Aida ◽  
Kotaro Kawamura
Keyword(s):  
Thermal Power ◽  
Reaction Force ◽  
High Energy ◽  
Scale Model ◽  
Design Parameters ◽  
Load Testing ◽  
Support Structure ◽  
Flange Thickness ◽  
Round Section ◽  
Energy Absorbing

This paper deals with new types of steel seismic ties, which are energy absorbing devices installed between boiler and its support structure. To enhance the aseismic reliability of the boiler and its support structure, energy absorbing capacities of the seismic ties must be increased. To increase the capacities, sectional shapes of the seismic ties have been optimally designed. Concretely, I-section seismic ties as new types have been gained by optimizing the design parameters, material (conventional carbon steel and low yield strength steel), sectional height, web thickness, flange thickness under conditions to maximize absorbing energy and to restrict the reaction force equal to or smaller than that of round-section current seismic tie. As a result of cyclic load testing using 1/3 scale model, it was verified that energy absorption of the new types of seismic ties were 16–23 % larger than that of the current seismic tie.

Earthquake Load Reduction Effects of Boiler Structures by High Energy Absorbing Seismic Ties

2014 ◽  
Author(s):  
Kiyoshi Aida ◽  
Kodai Kawate ◽  
Yuichi Hiyoshi ◽  
Kotaro Kawamura ◽  
Satoshi Fujita
Keyword(s):  
Energy Absorption ◽  
Shear Force ◽  
Seismic Waves ◽  
Time History ◽  
High Energy ◽  
Lumped Mass ◽  
Support Structure ◽  
Reduction Effect ◽  
Energy Absorbing ◽  
The Relationship

Seismic ties are steel energy absorbing devices installed between the boiler and its support structure. This paper deals with the relationship between the energy absorption of a new type of seismic tie (made of low yield strength steel and with an optimized I-sectional shape) and its reduction effect on the resultant shear force of the support structure. To quantify the relationship between the energy absorption and the reduction effect on the resultant shear force, time-history analyses using a lumped mass vibration model that simulates the boiler structure, were performed for three representative design seismic waves (The largest class (level 2) waves of Taft, El Centro and Hachinohe earthquakes). The time-history analysis results demonstrated that the energy absorption increasing rates of the new seismic ties were correlated quantitatively with the shear force reduction rates of the support structure for the three design seismic waves.

J1010503 Vibration Reduction Effects for Thermal Power Boiler Structures with High Energy Absorbing Seismic Ties

2014 ◽  
Vol 2014 (0) ◽  
pp. _J1010503--_J1010503-
Author(s):  
Kiyoshi AIDA ◽  
Masahiro IFUKU ◽  
Kodai KAWATE ◽  
Koutaro KAWAMURA ◽  
Satoshi FUJITA
Keyword(s):  
Thermal Power ◽  
Vibration Reduction ◽  
High Energy ◽  
Energy Absorbing ◽  
Power Boiler

Elasto-Plastic Finite Element Analysis of Long-Lived Seismic Ties for Thermal Power Boiler Structure

2017 ◽  
Author(s):  
Kiyoshi Aida ◽  
Shoji Morikawa ◽  
Masaki Shimono ◽  
Motoki Kato ◽  
Kunihiro Morishita ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Power ◽  
Support Structure ◽  
Element Analysis ◽  
Earthquake Loads ◽  
Energy Absorbing ◽  
Power Boiler

This paper deals with the modification of recently developed steel seismic ties, which are energy absorbing devices installed between a boiler and its support structure. To enhance the aseismic reliability of the boiler and its support structure for recently increased specified earthquake loads, the useful live of the seismic ties must be prolonged. To achieve this, changes to the sectional shapes of the seismic ties have been analyzed and designed with the help of elasto-plastic finite element analysis.

Automated simulation techniques for uncovering high-performance bioinspired cellular structures under blast loads

2021 ◽  
pp. 109963622110204
Author(s):  
Abdallah Ghazlan ◽  
Tuan Ngo ◽  
Tay Son Le ◽  
Tu Van Le
Keyword(s):  
Energy Dissipation ◽  
Trabecular Bone ◽  
Reaction Force ◽  
Blast Loading ◽  
Performance Criteria ◽  
Superior Performance ◽  
Cellular Structures ◽  
Design Parameters ◽  
Engineering Practice ◽  
Automated Simulation

Trabecular bone possesses a complex hierarchical structure of plate- and strut-like elements, which is analogous to structural systems encountered in engineering practice. In this work, key structural features of trabecular bone are mimicked to uncover effective energy dissipation mechanisms under blast loading. To this end, several key design parameters were identified to develop a bone-like unit cell. A computer script was then developed to automatically generate bone-like finite element models with many combinations of these design parameters, which were simulated under blast loading. The optimal structure was identified and its performance was benchmarked against traditional engineered cellular structures, including those with hexagonal, re-entrant and square cellular geometries. The bone-like structure showed superior performance over its engineered counterparts using the peak transmitted reaction force and energy dissipation as the key performance criteria.

Research on Parameters Matching of Ultralight Electric Aircraft Propulsion System

2013 ◽  
Vol 732-733 ◽  
pp. 1212-1215
Author(s):  
Gui Wen Kang ◽  
Yu Hu ◽  
Ya Dong Li ◽  
Wen Hui Jiang
Keyword(s):  
Electric Propulsion ◽  
High Energy ◽  
Low Noise ◽  
Electric Power System ◽  
Propulsion System ◽  
Heat Radiation ◽  
Design Parameters ◽  
Electric Propulsion System ◽  
Electric Aircraft ◽  
Parameter Matching

The propulsion system of ultralight electric aircraft is one of the general aviation technology development directions. It has the advantages such as light pollution, low noise, high energy utilization ratio, simple structure, easy maintenance, high reliability, less heat radiation, little operation cost and so on. Combined with the certain type of ultralight aircraft design parameters, the layout of aircraft electric propulsion, the principles and steps of the parameter matching of electric propulsion system were presented. The method of parameter matching and performance verification of electric propulsion system was put forward. The feasibility of the system is verified from the point of dynamic property. The study of parameter matching of electric propulsion system could not only provide basis for the integrated optimization for electric power system, but also evaluate the performance of the system simulation as reference.

Use of Digital Twins for Mathematical Modeling of Ultrasonic Cutting of Titanium Blanks

2021 ◽  
Vol 1037 ◽  
pp. 369-376
Author(s):  
Maxim Ilyushkin ◽  
Kirill Savelev ◽  
Oleg Krupennikov ◽  
Evgeniy S. Kiselev
Keyword(s):  
Mathematical Modeling ◽  
Thermal Power ◽  
Experimental Studies ◽  
Ultrasonic Field ◽  
Design Parameters ◽  
Digital Twins ◽  
Machine Parts ◽  
Cutting Processes ◽  
Stock Removal ◽  
Processing Zone

The paper presents the results of numerical experimental studies of cutting titanium blanks using mathematical modeling programs, which make it possible to completely repeat technological processes in a computer (digital twin). The LS-DYNA product was used as a program to simulate the process of stock removal from titanium blank. It has been established that the use of this method adequately describes the cutting processes, including with the introduction of the energy of an ultrasonic field into the processing zone, can significantly reduce the duration of experimental research and evaluate the influence of the elements of the cutting mode and design parameters of the tool on the thermal power aspects of the formation of new surfaces of machine parts.

scholarly journals Monitoring deformation of small scale model tunnels under load testing

Survey Review ◽  
2014 ◽  
Vol 46 (339) ◽  
pp. 417-425 ◽  
Author(s):  
H-M. Chen ◽  
M. Smith ◽  
H-S. Yu ◽  
N. Kokkas
Keyword(s):  
Scale Model ◽  
Small Scale ◽  
Load Testing ◽  
Small Scale Model

Effects of Rotating Blade Wakes on Separation and Pressure Recovery in Turbine Exhaust Diffusers

2008 ◽  
Author(s):  
Olaf Sieker ◽  
Joerg R. Seume
Keyword(s):  
Boundary Layer ◽  
High Energy ◽  
Flow Coefficient ◽  
Pressure Recovery ◽  
High Mass ◽  
Scale Model ◽  
Swirl Number ◽  
Annular Diffuser ◽  
Bladed Rotor ◽  
Turbine Exhaust

Highly efficient turbine exhaust diffusers can only be designed by taking into account the unsteady interactions with the last rotating row of the turbine. Therefore, a scale model of a typical gas turbine exhaust diffuser consisting of an annular and a conical diffuser is investigated experimentally. To investigate the influence of rotating wakes, a variable-speed rotating spoke wheel with cylindrical spokes as well as with NACA bladed spokes generates high-energy turbulent wakes simulating turbine rotor wakes. For the rotor with the NACA blades, the drive of the wheel is run in motor as well as in generator mode. Additional measurements in a reference configuration without a spoke wheel allow the detailed analysis of changes in the flow pattern. 3-hole pneumatic probes, static pressure taps, as well as a 2D-Laser-Doppler-Velocimeter (LDV) are used to investigate velocity profiles and turbulent characteristics. Without the wakes generated by a spoke wheel, the annular diffuser (with a 20° half cone opening angle) separates at the shroud for all swirl configurations. Increasing the swirl results in increasing pressure recovery at the shroud whereas the hub boundary is destabilized. For a non-rotating spoke rotor and low swirl numbers, the 20° annular diffuser separates at the shroud. Increasing the swirl number, a strong deceleration of the axial velocity at the shroud is generated without separation and a higher pressure recovery is achieved. The boundary layer at the shroud of the 20° annular diffuser separates for all operating points with the bladed rotor. A partly stabilized 20° annular diffuser can only be achieved for much higher values of the flow coefficient than that for the design point. At this high mass flow, the NACA-bladed rotor operates as a turbine, resulting in the generator mode of the electric drive. Contrary to the numerical design calculations, the flow at the shroud of a 15° annular diffuser does not separate for all swirl configurations in the experiment. Pressure recovery of the 15° annular diffuser can be increased by increasing the inlet swirl whereas the hub boundary layer is destabilized. For the NACA bladed rotor, the flow in the 15° annular diffuser as well as the pressure recovery strongly depend on the flow coefficient. For flow coefficients lower than the design value, the flow partly separates at the shroud whereas large flow coefficients result in increased pressure recovery. The pressure recovery also depends on the direction of swirl and thus the swirl number.

scholarly journals A reduced order computational model of a semi-active variable-stiffness foot prosthesis

2020 ◽  
Author(s):  
Michael McGeehan ◽  
Peter Adamczyk ◽  
Kieran Nichols ◽  
Michael Hahn
Keyword(s):  
Body Weight ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Variable Stiffness ◽  
Performance Standard ◽  
Design Parameters ◽  
Compression Tests ◽  
Static Compression ◽  
Lumped Parameter ◽  
Contact Models

INTRODUCTION: Passive energy storage and return (ESR) feet are the current performance standard in lower limb prostheses. A recently developed semi-active variable-stiffness foot (VSF) prosthesis balances the simplicity of a passive ESR device with the adaptability of a powered design. The purpose of this study was to model and simulate the ESR properties of the VSF prosthesis. METHODS: The ESR properties of the VSF were modeled as a lumped parameter overhung beam. The overhung length is variable, allowing the model to exhibit variable ESR stiffness. Foot-ground contact was modeled using sphere-to-plane contact models. Contact parameters were optimized to represent the geometry and dynamics of the VSF and its foam base. Static compression tests and gait were simulated. Simulation outcomes were compared to corresponding experimental data. RESULTS: Stiffness of the model matched that of the physical VSF (R2: 0.98, RMSE: 1.37 N/mm). Model-predicted resultant ground reaction force (GRFR) matched well under optimized parameter conditions (R2: 0.98, RMSE: 5.3% body weight,) and unoptimized parameter conditions (R2: 0.90, mean RMSE: 13% body weight). Anterior-posterior center of pressure matched well with R2 > 0.94 and RMSE < 9.5% foot length in all conditions. CONCLUSIONS: The ESR properties of the VSF were accurately simulated under benchtop testing and dynamic gait conditions. These methods may be useful for predicting GRFR arising from gait with novel prostheses. Such data are useful to optimize prosthesis design parameters on a user-specific basis.

scholarly journals Influence of pipeline geometry on hydrodynamics and heat transfer processes by an example of a ship steam generator

2021 ◽  
Vol 2088 (1) ◽  
pp. 012033
Author(s):  
O V Mitrofanova ◽  
A V Fedorinov
Keyword(s):  
Nuclear Power ◽  
Large Scale ◽  
Complex Geometry ◽  
Swirling Flow ◽  
Thermal Power ◽  
Design Parameters ◽  
Nuclear Power Installation ◽  
Wide Range ◽  
Nuclear Power Installations ◽  
Power Installations

Abstract The theoretical and computational analysis proposed in this work is aimed at identifying the features of thermal and hydrodynamic processes carried out in the steam-generating channels of the ship type water-moderated nuclear power installations. It is shown that the complex geometry of the thermohydraulic tract curvilinear channels of the steam generating system has a significant effect on the efficiency of the transport nuclear power installation. In addition to the formation of large-scale vortex structures and swirling flow in the pipeline, the phenomenon of the swirling flow crisis is revealed, under which the low-frequency component of the acoustic spectrum is enhanced. The scientific and applied significance of the proposed research is associated with the need to ensure a wide range of operational changes in efficient and safe operation power modes of icebreaker nuclear power installations. The research, aimed at developing the principles of physical and mathematical modeling of complex vortex flows, is necessary to optimize the design parameters of the thermal power equipment elements of new generation ship nuclear power installations in order to ensure increased safety and reliability of their operation.

Sign in / Sign up

Export Citation Format

Share Document