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.

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.

Principles and Practice of Modeling in CAD

2013 ◽  
Vol 753-755 ◽  
pp. 1299-1302 ◽  
Author(s):  
Josef Šedivý ◽  
Stepan Hubalovsky
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Structural Design ◽  
Computational Algorithm ◽  
Stress And Strain ◽  
Computer Aided ◽  
Loaded Part ◽  
Structural Boundary ◽  
3D Digital Models

Computer Aided Engineering are all tools for implementing of simulations and engineering calculations on 3D digital models and assemblies created in the CAD module. Computational algorithm works based on Finite Element Method - FEM. In connection with the design of structural design out strength calculations to determine the stress and strain in the loaded part of the structure is usually carried out. A network of elements is defined on a 3D digital model or assembly. Geometric and structural boundary conditions are specified according to functionality of construction.

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.

Metal Forming and the Finite-Element Method

1989 ◽  
Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Metal Forming ◽  
Computer Aided Design ◽  
The Finite Element Method ◽  
Forming Technology ◽  
Computer Aided ◽  
Deformation Mechanics ◽  
Aided Design ◽  
Element Method

The application of computer-aided design and manufacturing techniques is becoming essential in modern metal-forming technology. Thus process modeling for the determination of deformation mechanics has been a major concern in research . In light of these developments, the finite element method--a technique by which an object is decomposed into pieces and treated as isolated, interacting sections--has steadily assumed increased importance. This volume addresses advances in modern metal-forming technology, computer-aided design and engineering, and the finite element method.

scholarly journals Experimental & FEM Analysis of Orthodontic Mini-Implant Design on Primary Stability

2021 ◽  
Vol 11 (12) ◽  
pp. 5461
Author(s):  
Elmedin Mešić ◽  
Enis Muratović ◽  
Lejla Redžepagić-Vražalica ◽  
Nedim Pervan ◽  
Adis J. Muminović ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Primary Stability ◽  
Fem Analysis ◽  
Implant Design ◽  
Special Focus ◽  
Engineering System ◽  
Mini Implants ◽  
Pull Out ◽  
Computer Aided

The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.

scholarly journals Application of the erosion algorithm in modeling of structures behavior under impulse loads

2019 ◽  
Vol 221 ◽  
pp. 01003
Author(s):  
Pavel Radchenko ◽  
Stanislav Batuev ◽  
Andrey Radchenko
Keyword(s):  
Finite Element ◽  
High Velocity ◽  
Three Dimensional ◽  
Computer Software ◽  
Dynamic Loads ◽  
Complex Structures ◽  
Numerical Studies ◽  
Contact Surfaces ◽  
Fracture Of Materials ◽  
Solid Bodies

The paper presents results of applying approach to simulation of contact surfaces fracture under high velocity interaction of solid bodies. The algorithm of erosion -the algorithm of elements removing, of new surface building and of mass distribution after elements fracture at contact boundaries is consider. The results of coordinated experimental and numerical studies of fracture of materials under impact are given. Authors own finite element computer software program EFES, allowing to simulate a three-dimensional setting behavior of complex structures under dynamic loads, has been used for the calculations.

Investigation on endurance evaluation of a portal crane: experimental, theoretical and finite element analysis

2020 ◽  
Vol 62 (4) ◽  
pp. 357-364
Author(s):  
Yusuf Aytaç Onur ◽  
Hakan Gelen
Keyword(s):  
Finite Element ◽  
Critical Points ◽  
Maximum Stress ◽  
Strain Gages ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Element Simulation ◽  
Main Girder ◽  
Stressed Component ◽  
Portal Crane

Abstract In this study, the stress on portal crane components at various payloads has been investigated theoretically, numerically and experimentally. The portal crane was computer-aided modeled and finite element analyses were performed so that the most stressed points at the each trolley position investigated on the main girder could be determined. In addition, the critical points were marked on the portal crane, and strain gages were attached to the those critical points so that stress values could be experimentally determined. The safety factor values at different payloads were determined by using finite element simulation. Results indicate that the most stressed component in the examined portal crane is the main girder. Experimental results indicate that the maximum stress value on the main girder is 3.05 times greater than the support legs and 8.99 times larger than the rail.

Strength-based design of a sunflower stalk cutter machine design using finite element analysis and experimental validation

2021 ◽  
pp. 095440622110597
Author(s):  
Gürkan İrsel
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Strain Gage ◽  
Experimental Validation ◽  
Experimental Studies ◽  
Fatigue Analysis ◽  
Structural Stress ◽  
Element Analysis ◽  
Strength Based

In this study, the total algorithm of the strength-based design of the system for mass production has been developed. The proposed algorithm, which includes numerical, analytical, and experimental studies, was implemented through a case study on the strength-based structural design and fatigue analysis of a tractor-mounted sunflower stalk cutting machine (SSCM). The proposed algorithm consists of a systematic engineering approach, material selection and testing, design of the mass criteria suitability, structural stress analysis, computer-aided engineering (CAE), prototype production, experimental validation studies, fatigue calculation based on an FE model and experimental studies (CAE-based fatigue analysis), and an optimization process aimed at minimum weight. Approximately 85% of the system was designed using standard commercially available cross-section beams and elements using the proposed algorithm. The prototype was produced, and an HBM data acquisition system was used to collect the strain gage output. The prototype produced was successful in terms of functionality. Two- and three-dimensional mixed models were used in the structural analysis solution. The structural stress analysis and experimental results with a strain gage were 94.48% compatible in this study. It was determined using nCode DesignLife software that fatigue damage did not occur in the system using the finite element analysis (FEA) and experimental data. The SSCM design adopted a multi-objective genetic algorithm (MOGA) methodology for optimization with ANSYS. With the optimization solved from 422 iterations, a maximum stress value of 57.65 MPa was determined, and a 97.72 kg material was saved compared to the prototype. This study provides a useful methodology for experimental and advanced CAE techniques, especially for further study on complex stress, strain, and fatigue analysis of new systematic designs desired to have an optimum weight to strength ratio.

scholarly journals Agustin de Betancourt’s Mechanical Dredger in the Port of Kronstadt: Analysis through Computer-Aided Engineering

2018 ◽  
Vol 8 (8) ◽  
pp. 1338 ◽  
Author(s):  
José Rojas-Sola ◽  
Eduardo De la Morena-De la Fuente
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
3D Model ◽  
Russian Empire ◽  
Computer Aided Engineering ◽  
Operating Conditions ◽  
The Finite Element Method ◽  
Safety Coefficient ◽  
Computer Aided ◽  
The Russian Empire

This article analyzes the first self-propelled floating dredging machine designed and executed by Agustín de Betancourt in 1810 to dredge the port of Kronstadt (Russia). With this objective, a study of computer-aided engineering (CAE) has been carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite element method, of the 3D model which is reliable under operating conditions. The results have shown that the system of inertia drums proposed by Betancourt manages to dissipate the tensions between the different elements, locating the highest stresses in the links of the bucket rosary, specifically at the point of contact between links. Similarly, the maximum displacements and the greatest deformations (always associated with these points of greater stress), are far from reaching the limits of breakage of the material used in its construction, as well as the safety coefficient of the invention, confirming that the mechanism was oversized, as was generally the case at the time. This analysis highlights the talent of the Spanish engineer and his mastery of mechanics, in an invention, the first of its kind worldwide, which served the Russian Empire for many years.

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