Acceleration Response Mode Decomposition for Quantifying Wave Impact Load in High-Speed Planing Craft

2014 ◽  
Author(s):  
Michael R. Riley ◽  
Timothy W. Coats ◽  
Heidi Murphy
Keyword(s):  
High Speed ◽  
Impact Load ◽  
Response Mode ◽  
Acceleration Response ◽  
Wave Impact ◽  
Planing Craft ◽  
Mode Decomposition

Lessons Learned from Full-Scale Seakeeping Trial Acceleration Data for HighSpeed Planing Craft and Implications for Scale Model Testing

2017 ◽  
Author(s):  
Michael R. Riley ◽  
Timothy Coats
Keyword(s):  
High Speed ◽  
Impact Load ◽  
Maximum Load ◽  
Model Testing ◽  
Full Scale ◽  
Lessons Learned ◽  
Scale Model ◽  
Wave Impact ◽  
Acceleration Data ◽  
Hull Structure

This paper summarizes lessons learned from analyzing acceleration data recorded during full-scale seakeeping trials of high speed craft. Applications using a consistent maximum wave impact load approach in different areas of interest, including hull structure, shock isolation seat evaluation, and equipment ruggedness criteria are presented. The lessons learned and the maximum load applications suggest that there are implications for scale model testing and computational fluid dynamics.

A Method to Quantify Mitigation Characteristics of Shock Isolation Seats Before Installation in a High-Speed Planing Craft

2015 ◽  
Author(s):  
Michael R. Riley ◽  
Timothy W. Coats ◽  
Heidi P. Murphy ◽  
Neil Ganey
Keyword(s):  
High Speed ◽  
Historical Perspective ◽  
Lessons Learned ◽  
Computational Method ◽  
Impact Loads ◽  
Wave Impact ◽  
New Approach ◽  
Planing Craft ◽  
Acceleration Data ◽  
Shock Isolation

This paper presents a new approach for quantifying the mitigation achieved by a passive marine shock isolation seat. A brief historical perspective is summarized to explain why common myths have evolved that has led to seats being integrated into craft only to find out during subsequent seakeeping trials that the seats provide little to no mitigation or that they actually amplify wave impact loads. Acceleration data is presented to demonstrate use of the new computational method and the lessons learned are explained in terms that support development of a standard for laboratory seat testing.

Coupled Fluid-Structural Modelling to Predict Wave Impact Loads on High-Speed Planing Craft

2001 ◽  
Author(s):  
Simon Rees ◽  
◽  
David Reed ◽  
Colin Cain ◽  
Bob Cripps ◽  
...  
Keyword(s):  
High Speed ◽  
Impact Loads ◽  
Structural Modelling ◽  
Wave Impact ◽  
Planing Craft

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

Study on Vibration Signal Marginal Spectrum of Paper-Transferring System in Printing Press Based on EMD

2010 ◽  
Vol 139-141 ◽  
pp. 2464-2468
Author(s):  
Yi Ming Wang ◽  
Shao Hua Zhang ◽  
Zhi Hong Zhang ◽  
Jing Li
Keyword(s):  
Empirical Mode Decomposition ◽  
Optimization Design ◽  
Impact Load ◽  
Vibration Signal ◽  
Key Factors ◽  
Mode Function ◽  
Mode Decomposition ◽  
Marginal Spectrum ◽  
Periodic Signals ◽  
The Moment

The precision of transferring paper is key factors to decide the print overprint accuracy, and vibration has an important impact on paper transferring accuracy. Empirical mode decomposition (EMD) can be used to extract the features of vibration test signal. According to the intrinsic mode function (IMF) by extracted, it is useful to analyze the dynamic characteristics of swing gripper arm on motion state. Due to the actual conditions of printing, the vibration signal of Paper-Transferring mechanism system is complex quasi periodic signals. Hilbert-Huang marginal spectrum that is based on empirical mode decomposition can solve the problem which is modals leakage by FFT calculated in frequency domain. Through the experimental research, the phase information of impact load at the moment of grippers opening or closing, which can be used for the optimization design of Paper-Transferring system and the improvement in the accuracy of swing gripper arm.

scholarly journals DYNAMIC BEHAVIOR OF REINFORCED CONCRETE COLUMN UNDER ACCIDENTAL IMPACT

2021 ◽  
Vol 17 (3) ◽  
pp. 120-131
Author(s):  
Sergey Savin ◽  
Vitaly Kolchunov
Keyword(s):  
Reinforced Concrete ◽  
Analytical Solution ◽  
High Speed ◽  
Impact Load ◽  
Dynamic Buckling ◽  
Shock Load ◽  
Dynamic Factor ◽  
Physical Parameters ◽  
Concrete Column ◽  
Reinforced Concrete Column

The analysis of scientific literature shows that to date, the physical parameters of the deformation of reinforced concrete bar structures during their dynamic buckling and the influence of the dissipative properties of the structural system on this process remain insufficiently studied. In this regard, the paper proposes an analytical solution to the problem of dynamic buckling of a reinforced concrete column when it is loaded with an impact load, taking into account the presence of initial geometric and (or) physical imperfections and damping properties of the system, as well as an analysis and assessment of the column deformationparameters based on the obtained analytical solution. An expression for the dynamic deflection of a bar element under its axial loading with a high-speed shock load, taking into account damping, is obtained in an analytical form. For practical calculations in a quasi-static formulation, the paper proposes an expression for the dynamic factor kd of bar structures under axial shock load. A numerical example of calculating a reinforced concrete column using the obtained analytical expressions with and without damping is considered. It was found that the maximum deflection of the elastic axis of the column under high-speed loading was achieved at t = 0.04 s. In this case, the total dynamic deflection taking into account damping was 4.8% less than the deviation without taking into account damping and 1.18 times more than the corresponding static value.

scholarly journals An Experimental Investigation of Ride Control Algorithms for High-Speed Catamarans Part 2: Mitigation of Wave Impact Loads

2017 ◽  
Vol 61 (2) ◽  
pp. 51-63 ◽  
Author(s):  
Javad AlaviMehr ◽  
Jason Lavroff ◽  
Michael R. Davis ◽  
Damien S. Holloway ◽  
Giles A. Thomas
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
Control Algorithms ◽  
Impact Loads ◽  
Wave Impact ◽  
Ride Control

Development and Optimization of Mathematical Model of High Speed Planing Dynamics

2015 ◽  
Author(s):  
Prin Kanyoo ◽  
Dominic J. Taunton ◽  
James I. R. Blake
Keyword(s):  
Relative Velocity ◽  
High Speed ◽  
Lift Force ◽  
Hydrodynamic Pressure ◽  
Physical Nature ◽  
Ship Motions ◽  
Additional Contribution ◽  
Forward Speed ◽  
Planing Craft ◽  
Hydrostatic Force

The primary difference between a planing craft and a displacement ship is that the predominant force to support the conventional or displacement craft is hydrostatic force or buoyancy. While in the case of planing craft, the buoyancy cedes this role to hydrodynamic lift force caused by flow and pressure characteristics occurring when it is travelling at high forward speed. However, the magnitude of hydrostatic force is still significant that cannot be completely neglected. Due to the high forward speed and trim angle, the flow around and under the planing hull experiences change of momentum and leads to the appearance of lift force according to the 2ndlaw of Newton. In other words, there is a relative velocity between the craft hull and the wave orbital motion that causes hydrodynamic pressure generating hydrodynamic lift force act on the hull surface. Then, in case of behaviors in waves, an additional contribution of ship motions is necessary to be considered in the relative velocity, resulting in nonlinear characteristic of its physical nature.

A REAL TIME SPEED MODULATION SYSTEM TO IMPROVE OPERATIONAL ABILITY OF AUTONOMOUS PLANING CRAFT IN A SEAWAY

2021 ◽  
Vol 162 (A4) ◽  
Author(s):  
H Allaka ◽  
A Levy ◽  
D Levy ◽  
T Triebitz ◽  
M Groper
Keyword(s):  
High Speed ◽  
Structural Integrity ◽  
Planing Craft ◽  
Speed Modulation ◽  
Angular Velocities ◽  
Operational Ability ◽  
Vertical Accelerations ◽  
Predicted Values ◽  
Safety Operation ◽  
Motion Assessment

This study focuses on developing a control system to enhance the seaworthiness of Autonomous high-speed Planing Crafts (APCs). APCs operating at high-speed in a seaway encounter very high vertical accelerations which pose a hazard to payload and crafts' structural integrity. Therefore, for safety operation of APCs in a seaway it is proposed to employ a system termed vision-aided speed modulation system (VSMS). The proposed VSMS employs an embedded analytical tool termed Motion Assessment of Planing Craft in a Seaway (MAPCS) for the prediction of vertical accelerations and angular velocities, the APC might encounter in the incoming waves. As a response to the MAPCS predicted values the VSMS speed setting module modulates the craft's forward speed. All modules of the VSMS are presented together with their validation and system's preliminary operational results. It is concluded that VSMS might be an essential tool to considerably enhance the operational ability of APCs. 

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