Improvements in Data Acquisition for Propulsion Shaft Alignment

2015 ◽  
Author(s):  
W. David Joiner ◽  
Charles J. Cook
Keyword(s):  
Data Acquisition ◽  
Strain Gage ◽  
Strain Gages ◽  
Construction Process ◽  
Crucial Step ◽  
Ship Construction ◽  
Shaft Line ◽  
Load Cells ◽  
Shaft Alignment

Propulsion shaft alignment is a necessary and crucial step in the ship construction process, with manning and schedule constraints requiring accurate results as efficiently as possible. There are two methods for measuring the bearing loading along the shaft line: strain gages and load cells. The legacy method for using strain gages required a lot of man power and the legacy method for using load cells was dependent on the quality of machinist made available. Strain gages are the transducers of choice for measurement; however the data acquisition, especially for ships with long shafting systems, can require many strain gage positions and personnel to conduct tests. Load cells are used to validate the accuracy of the strain gage method and to calculate the shaft runout at each bearing location.

Shaft Alignment Using Strain Gages

1981 ◽  
Vol 18 (03) ◽  
pp. 276-284
Author(s):  
Albert W. Forrest ◽  
Richard F. Labasky
Keyword(s):  
Strain Gage ◽  
Error Bounds ◽  
Bending Moment ◽  
Bending Moments ◽  
Strain Gages ◽  
Alignment Procedure ◽  
Determinate System ◽  
Shaft Alignment ◽  
Simplified Procedure ◽  
Hydraulic Jacking

A detailed description of the strain-gage shaft alignment procedure is presented, including a comparison between bearing reactions obtained using strain gages and hydraulic jacking. The various gage configurations available for measuring bending moments are discussed and estimates of the resulting error in bending moment are given. A simplified procedure is presented to calculate bearing reactions from the measured moments. Gage site requirements to produce a determinate system are established and a method is outlined to establish bearing reaction error bounds for a combination of gage configurations and sites.

Computer-Aided Alignment of Ship Propulsion Shafts by Strain-Gage Methods

1991 ◽  
Vol 28 (02) ◽  
pp. 84-90
Author(s):  
M. N. Keshava Rao ◽  
M. V. Dharaneepathy ◽  
S. Gomathinayagam ◽  
K. Ramaraju ◽  
P. K. Chakravorty ◽  
...  
Keyword(s):  
Finite Element ◽  
Strain Gage ◽  
Computational Algorithm ◽  
Computer Software ◽  
Strain Gages ◽  
Operational Conditions ◽  
Numerical Example ◽  
Computer Aided ◽  
Shaft Alignment ◽  
Working Out

A generalized procedure to compute all bearing reactions using finite-element and strain-gage techniques is explained. A computational algorithm for computing optimum bearing offsets both for new design as well as existing ships to get optimum bearing reactions is presented along with a numerical example. Advantages of the strain-gage method over other methods in working out a proper shaft alignment are described. A procedure to estimate the existing reactions in all bearings with the aid of strain gages, even for the case of three inaccessible bearings, is explained. By this feature, the strain-gage method is shown to be complete in itself and need not be supplemented by other conventional methods. An ideal architecture for shaft alignment computer software is explained. A technique for online shaft diagnosis in operational conditions using strain gages and onboard computers is shown.

Shaft Alignment Using Strain Gages: Case Studies

1999 ◽  
Vol 36 (02) ◽  
pp. 77-91
Author(s):  
Bruce Cowper ◽  
Al DaCosta ◽  
Stephen Bobyn
Keyword(s):  
Mathematical Modeling ◽  
Case Studies ◽  
Strain Gage ◽  
The Other ◽  
Strain Gages ◽  
Traditional Methods ◽  
Alignment Condition ◽  
Shaft Alignment ◽  
Marine Vessels ◽  
Optical Laser

Two case studies are presented in which measurement and modeling programs were undertaken to assess the installed shaft alignment condition on marine vessels. One on the CCGS Earl Grey, and the other on the HMCS Huron. In both cases catastrophic damages had previously occurred to shaftline components, which were suspected to be a result of shaft mis-alignment. The damaged components were repaired, and the shaftlines were re-aligned using traditional methods (optical/laser). To assess the alignment condition of the installed shaftlines, measurements were taken by using the strain gage technique. In one case the shaft was realigned according to the strain gage measurements. Mathematical modeling was also conducted to assess the implications of the alignment measurements, and to provide the means to estimate the offsets of the installed bearings from their prescribed positions.

Shaft Alignment Methods with Strain Gages and Load Cells

1980 ◽  
Vol 17 (01) ◽  
pp. 8-15
Author(s):  
Robert B. Grant
Keyword(s):  
Reduction Gear ◽  
Bending Moments ◽  
Strain Gages ◽  
Direct Bearing ◽  
Load Cells ◽  
Shaft Alignment

The paper presents methods of aligning propulsion shafting using load cells for direct bearing reaction measurement and procedures for shafting alignment by measurement of shaft bending moments with strain gages. Additionally, a unique means of measuring reduction gear and stern tube bearing reactions is described.

Development and Application of Quality Control System for Highway Subgrade Construction

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Detection Method ◽  
System Development ◽  
Effective Control ◽  
Construction Process ◽  
Development Mode ◽  
The Road ◽  
Whole Process

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.

Quality Monitoring System for Seismic While Drilling

2013 ◽  
Vol 318 ◽  
pp. 572-575
Author(s):  
Li Li Yu ◽  
Yu Hong Li ◽  
Ai Feng Wang
Keyword(s):  
Data Acquisition ◽  
Monitoring System ◽  
Signal Analysis ◽  
Quality Evaluation ◽  
Quality Monitoring ◽  
Quality Of Data ◽  
Whole Process ◽  
Engineering Parameters ◽  
Network Status

In this paper a quality monitoring system for seismic while drilling (SWD) that integrates the whole process of data acquisition was developed. The acquisition equipment, network status and signals of accelerometer and geophone were monitored real-time. With fast signal analysis and quality evaluation, the acquisition parameters and drilling engineering parameters can be adjusted timely. The application of the system can improve the quality of data acquisition and provide subsequent processing and interpretation with high qualified reliable data.

Evaluating the quality of strain gage waterproofing compounds

Strain ◽  
1972 ◽  
Vol 8 (2) ◽  
pp. 81-81
Author(s):  
GERALD R. DITTBENNER
Keyword(s):  
Strain Gage

scholarly journals Development and evaluation of an automated system for testing current meters

2016 ◽  
Vol 20 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Ezequiel Saretta ◽  
Antonio P. de Camargo ◽  
Tarlei A. Botrel ◽  
Marinaldo F. Pinto ◽  
Geancarlo T. Katsurayama ◽  
...  
Keyword(s):  
User Interface ◽  
Data Acquisition ◽  
Flow Velocity ◽  
Reference Value ◽  
Vertical Axis ◽  
Automated System ◽  
Step Motor ◽  
Simple Task ◽  
Rivers And Streams

ABSTRACT Current meters are equipment widely used for estimating flow velocity in rivers and streams. Periodic calibrations of current meters are important to ensure the quality of measurements, but the required testing facilities are complex and only available in a few institutions. However, advances in electronics and automation may contribute to developing simple and reliable calibration systems. Thus, this study aimed to develop an automated system for testing current meters, which consisted of a trapezoidal channel, a step motor, a tow car and a management system, composed of a supervisory application and microprocessed modules to control the motor and the data acquisition. Evaluations of the displacement velocity showed that it matched the reference value up to 1.85 m s-1 for a vertical-axis current meter and 2.3 m s-1 for a horizontal-axis one. The developed system showed reliability during tests, for both current meter movement and data acquisition. The management of the system based on the developed modules and the supervisory application improved its user interface, turning all the procedure into a simple task.

Specimen Molding Method of Chip Seal in Laboratory

2011 ◽  
Vol 374-377 ◽  
pp. 1904-1907
Author(s):  
Yu Hua Li ◽  
Hai Xiang Li ◽  
Yu Xing Liu ◽  
Jing Yun Chen
Keyword(s):  
Asphalt Concrete ◽  
Visual Inspection ◽  
Performance Test ◽  
Construction Process ◽  
Molding Method ◽  
Chip Seal ◽  
Sand Patch ◽  
Emulsified Asphalt ◽  
Cushion Layer

Chip seal is most frequently used as preventive maintenance (PM) treatments on asphalt pavement. However, it’s difficult to make the performance test of chip seal in laboratory. In this paper, the specimen molding method of chip seal is established in laboratory. Firstly, considering the structure and technique condition of the original pavement, a cushion layer of asphalt concrete (AC) is used as under layer of the specimen. Secondly, the construction process of chip seal is simulated in laboratory, which includes spraying emulsified asphalt and/or glass fiber, spreading aggregate, initial rolling and conservation, post-stage rolling and conservation in interval for some time. Lastly, visual inspection and sand patch test are used to evaluate the quality of the specimen. Research results show that the method of specimen molding and test in laboratory could relatively accurately simulate, evaluate and forecast the performance of the chip seal.

scholarly journals THE RISKS AND LIABILITY OF PARTICIPANTS OF A CONSTRUCTION PROCESS FOR DEFECTS OF BUILDING PRODUCTS

2004 ◽  
Vol 10 (3) ◽  
pp. 109-115 ◽  
Author(s):  
Sigitas Mitkus
Keyword(s):  
Construction Projects ◽  
Building Materials ◽  
Legal Regulation ◽  
The Other ◽  
Construction Process ◽  
Building Products ◽  
Construction Contracts ◽  
And Behavior ◽  
Mutual Agreement

Sharing of the risk and liability is one of the most important functions of construction contracts. Proper sharing of the risks and liability between the parties of construction contract has a rather big influence on efficiency, quality, and probability of arising disputes between the parties of construction contract in construction projects. A lot of risk exists during the fulfillment of construction projects. One of those risks is the risk of defects of building products. The question of the liability of the parties of construction contract for inappropriate quality of the construction production caused by a bad quality of building products mainly depends on sharing of the risk of defects of building materials in the construction contract. Some aspects of the mentioned risk and liability of the parties of the construction contract might be set by mutual agreement in the construction contract. The other aspects are regulated by imperative norms of the law and the parties of construction contract have not a right to change those imperative conditions of sharing of risks and liability. The article deals with sharing of risk and liability for supplying building products of an improper quality for construction, taking in to account conditions of construction contract, legal regulation and behavior of parties of a construction contract. A tree of forming the alternatives of liability is presented in the article. Liability for supply of defected building products arises not only for parties of a construction contract. The producer (supplier) of building products is responsible for this as well. Variations of liability of the producer (supplier) depending on construction contract conditions are analyzed. A matrix of liability of the producer (supplier) of building products is presented in the article.

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