Design Guidelines for Dynamic Stability of Tainter Gates

2017 ◽  
Author(s):  
Keiko Anami ◽  
Noriaki Ishii ◽  
Charles W. Knisely ◽  
Tatsuya Oku
Keyword(s):  
Dynamic Stability ◽  
Fem Analysis ◽  
Design Guidelines ◽  
Design Stage ◽  
Actual Structure ◽  
Analysis And Design ◽  
Coupled Mode ◽  
Excited Vibration ◽  
Vibration Tests

To ensure the long-term safe operation of newly constructed Tainter gates, methods of analysis and design criteria are needed in the design stage to assure the dynamic stability of any new Tainter gate. For this purpose, the present study provides a detailed procedure for the dynamic design of Tainter gates that can be applied to preliminary designs by gate engineers to assure the dynamic stability of their gate designs. The dynamic stability of the gate can be determined using the natural vibration characteristics ascertained by finite element method (FEM) analysis, reasonable values of actual structure damping actually measured by the field vibration tests, and theoretical analysis of the coupled-mode self-excited vibration that has been previously established by authors. The procedure and the important points of each step are detailed in an example determination of the dynamic stability of a practical Tainter gate.

Coupled-Mode Dynamic Instability of Tainter Gates With Parallel Bending Vibration of the Skinplate

2010 ◽  
Author(s):  
Keiko Anami ◽  
Noriaki Ishii ◽  
Takuma Tsuji ◽  
Tatsuya Oku ◽  
Masaru Goto ◽  
...  
Keyword(s):  
Dynamic Instability ◽  
Laboratory Model ◽  
Dynamic Coupling ◽  
Bending Vibration ◽  
Coupled Mode ◽  
Excited Vibration ◽  
Rotational Vibration ◽  
The Usa ◽  
Vibration Mechanism ◽  
Vibration Tests

As part of the investigation of the dynamic instability of the gate closely related to the Folsom Dam Tainter-gate failure, and in order to assure the dynamic stability of the gate, the field vibration tests on three full-scale operational Tainter-gates were conducted. From these tests, the possible existence of another coupled-mode self excited vibration mechanism, which involves the dangerous dynamic coupling of the whole gate rigid-body rotational vibration with a “parallel” bending vibration of the skinplate was suggested. This paper presents the mechanism of the suggested coupled-mode self-excited vibration, theoretical analysis for the suggested dynamic instability, and 2-dimensional laboratory model tests results. Further, the need for retrofit countermeasures for Tainter gates which are currently installed in both Japan and the USA and susceptible to this dangerous coupled-mode dynamic instability is emphasized.

3715 Coupled-Mode Self-Exited Vibration Tests with 3D Large-Scaled Tainter-Gate Model : Examination about Friction-Maintained Dynamic Stability

2006 ◽  
Vol 2006.7 (0) ◽  
pp. 57-58
Author(s):  
Keiko ANAMI ◽  
Noriaki ISHII ◽  
Tatsuya OKU ◽  
Satoshi SASAKI ◽  
Naoto TERAKAWA
Keyword(s):  
Dynamic Stability ◽  
Coupled Mode ◽  
Vibration Tests

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

scholarly journals Analysis and Design for Output Voltage Regulation in Constant-on-Time-Controlled Fly-Buck Converter

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1886
Author(s):  
Younghoon Cho ◽  
Paul Jang
Keyword(s):  
Output Voltage ◽  
Voltage Regulation ◽  
Design Guidelines ◽  
Buck Converter ◽  
Design Guideline ◽  
Analysis And Design ◽  
Flyback Converter ◽  
Auxiliary Power ◽  
Primary Output ◽  
Output Capacitor

Fly-buck converter is a multi-output converter with the structure of a synchronous buck converter structure on the primary side and a flyback converter structure on the secondary side, and can be utilized in various applications due to its many advantages. In terms of control, the primary side of the fly-buck converter has the same structure as a synchronous buck converter, allowing the constant-on-time (COT) control to be applied to the fly-buck converter. However, due to the inherent energy transfer principle, the primary-side output voltage regulation of COT controlled fly-buck converters may be poor, which can deteriorate the overall converter performance. Therefore, the primary output capacitor must be carefully designed to improve the voltage regulation characteristics. In this paper, a theoretical analysis of the output voltage regulation in COT controlled fly-buck converter is conducted, and based on this, a design guideline for the primary output capacitor considering the output voltage regulation is presented. The validity of the analysis and design guidelines was verified using a 5 W prototype of the COT controlled fly-buck converter for telecommunication auxiliary power supply.

An Enhanced Hybrid Springback Compensation Approach: Springback Path – Displacement Adjustment Method For Complex Shaped Products of Sheet Metal Forming

2021 ◽  
Author(s):  
Zhihui Gong ◽  
Mandeep Singh ◽  
Bohao Fang ◽  
Dongbin Wei
Keyword(s):  
Sheet Metal ◽  
Automobile Industry ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
High Strength Steels ◽  
Fem Analysis ◽  
High Strength ◽  
Design Stage ◽  
Springback Compensation ◽  
Compensation Approach

Abstract Springback compensation is critical in sheet metal forming. Advanced techniques have been adopted in the design stage of various sheet metal forming processes, e.g. stamping, some of which are for complex shaped products. However, the currently available numerical approaches are not always sufficiently accurate and reliable. To improve the accuracy of springback compensation, an enhanced hybrid springback compensation method named Springback Path – Displacement Adjustment (SP-DA) method has been developed in this study based on the well-known conventional displacement adjustment (DA) method. Its effectiveness is demonstrated using FEM analysis of low, medium and high strength steels adopted in automobile industry, in which a symmetrical model owning geometry complexity similar to an auto body panel was established. The results show this new enhanced SP-DA method is able to significantly improve the accuracy of springback compensation comparing to conventional displacement adjustment technique.

scholarly journals Overview of Analytical Methods for Lubricated Engine Components

2007 ◽  
Author(s):  
Fanghui Shi
Keyword(s):  
System Analysis ◽  
Noise Analysis ◽  
Research Literature ◽  
Design Stage ◽  
Solution Technique ◽  
Connecting Rod ◽  
Component Level ◽  
Analysis And Design ◽  
Engine Components ◽  
Level 2

Engine designs require better fuel economy, lower NVH, and longer durability. Consequently, the understanding, analysis and design for lubricated engine components that have relative moving surfaces play an important role in this objective. As the GM corporate standard analytical tool for these components, FLARE has been under continuous improvements and validations since its first rollout from GMR in the late 80s. It has also been benchmarked with the best features available in the commercial software package and research literature. There are currently more than 20 standard work procedures directly involving FLARE as solver and its applications span over: • Rod, crank, cam and balance shaft journal bearings; • Connecting rod structure; • Piston structure and scuffing; • Engine mechanical friction; • Load calculation for engine block structural analysis; • Lube system analysis; • Noise analysis. There are three levels of analysis based on requirements. Namely, level one is used in initial design stage that finds solution by interpolating the curve-fitted equations. It requires the least information about the design and runs in seconds. In level 2, a more detailed solution can be obtained by solving mixed mass-conserving lubrication governing equations using FEM with the assumption of rigid bounding surfaces. Heat transfer can be taken into account in this level and above. Level 3 has the full capability, in addition to the features in level 2, the solution is coupled with the elasticity of surface/structure which can be obtained through offline structure FEM analysis. Higher level of analysis captures more physics but requires better understanding of the input parameters and careful interpretation of the results. The unique strength of FLARE is its detailed component level analysis capability. This presentation is an overview of the latest development on FLARE technology. It includes the physics captured in FLARE, integrated solution technique and some selected results for crankshaft bearings, floating piston pins, and piston/liner impact under partial film lubrication.

FEM Analysis of an Amphibious Hydraulic Excavator’s Boom and Stick

2011 ◽  
Vol 215 ◽  
pp. 336-339
Author(s):  
F.R. Tian ◽  
Z.C. Han
Keyword(s):  
Fem Analysis ◽  
Hydraulic Excavator ◽  
Sectional Area ◽  
Analysis Method ◽  
Comparison Analysis ◽  
Construction Machinery ◽  
Analysis And Design ◽  
Practical Design ◽  
Analysis Of Results ◽  
Machinery Design

Force conducted to boom and stick is analyzed by complicated elements divide of FEM, it shows that the more the box section is, the more load is, and Hinge point’s force is much more than before. If size isn’t be affected, it can be reduced by increasing the sectional area. FEM analysis and design comparison analysis results show that FEM analysis method is feasible to amphibious hydraulic excavator. FEM analysis of results to practical design provides a practical way and means for the process of other construction machinery design analysis.

Automation of Wind Pressure Computation Using a Data Management Approach

1993 ◽  
Author(s):  
Yamini Gourishankar ◽  
Frank Weisgerber
Keyword(s):  
Data Management ◽  
Data Retrieval ◽  
Design Guidelines ◽  
Database Management System ◽  
Information Modeling ◽  
Wind Pressure ◽  
Management Approach ◽  
Analysis And Design ◽  
Design Requirements ◽  
Wind Pressures

Abstract It is observed that calculating the wind pressures on structures involves more data retrieval from the ASCE standard than any subjective reasoning on the designer’s part. Once the initial design requirements are established, the procedure involved in the computation is straightforward. This paper discusses an approach to automate the process associated with wind pressure computation on one story and multi-story buildings using a data management strategy (implemented using the ORACLE database management system). In the prototype system developed herein, the designer supplies the design requirements in the form of the structure’s exposure type, its dimensions and the nature of occupancy of the structure. Using these requirements, the program retrieves the necessary standards data from an independently maintained database, and computes the wind pressures. The final output contains the wind pressures on the main wind force resisting system, and on the components and claddings, for wind blowing parallel and perpendicular to the ridge. The knowledge encoded in the system was gained from ASCE codes, design guidelines and as a result of interviews with various experts and practitioners. Several information modeling methodologies such as the entity relationship model, IDEF 1X, etc. were employed in the system analysis and design phase of this project. The prototype is implemented on an IBM PC using the ORACLE DBMS and the ‘C’ programming language. Appendix A illustrates a sample run.

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