bluuebunny/crossref_metadata_2025 huggingface dataset:
Machining Induced Defects and the Influence Factors when Diamond Turning of SiCp/Al Composites
Authors: Ge Y.F. , Xu Jiu Hua , Yang Hui , Luo S.B. , Fu Yu Can
Published: March 2009

Ultra-precision turning tests on SiCp/2024Al and SiCp/ZL101A composites were carried
out to investigate the surface quality using single point diamond tools (SPDT) and polycrystalline
diamond (PCD) cutters. Examined by SEM, the machined surfaces took on many defects such as
pits, voids, microcracks, grooves, protuberances, matrix tearing and so on. The results showed that
surface quality debased with increasing feed rate or using of high volume fraction materials. Dry
cutting would deteriorate the surface finish. It was also pointed out that SPDT outperformed PCD
tools although they produced the same surface roughness Ra. Microhardness measuring showed that
the deformation layer was extended to 8–16μm below the machined surface.
Research on Open-Loop Control of a Microactuator with High-Resolution and Large-Stroke Based on Inverse Preisach Model
Authors: Jiang W.R. , Lu Ze Sheng
Published: March 2009

The hysteresis in piezoelectric actuator is the main factor that affects its displacement accuracy, the hysteresis model is set up by using the theory of preisach, and the research on open-loop control of piezoelectric actuator is carried out based on inverse preisach model. The result shows that the model can describe successfully the hysteresis in piezoelectric actuator, predict the displacement after a series of random voltage path perfectly, and improve the hysteresis of displacement effectively, decrease the nonlinear error of system, increase control precision. A new microactuator with high-resolution and large-stroke based on piezoelectric is presented, and the open-loop control is investigated based on inverse preisach model, its stroke is 300mm, the position accuracy is about 0.03μm, the displacement resolution is up to 0.02μm.
Optimal Selection of Tool Geometry by Finite Element Simulation
Authors: Zhang Sheng Wen , Gong Chan Yuan , Fang Xi Feng , Wang Gui Cheng
Published: March 2009

The effect of cutting tool geometry on cutting process is very prominent and cannot be ignored, especially the interactions between tool geometries. In this study, the effects of the rake angle, the clearance angle, the cutting edge radius and the interaction between rake angle and clearance angle on cutting force and cutting temperature are numerically investigated using finite element method. Four-factor three-lever orthogonal experimental design is adopted in the finite element simulation of orthogonal cutting process. An analysis of range is performed to identify significant trends in the cutting force and cutting temperature and the optimal level values of each factor. The result shows that the effect of the rake angle on cutting force is significant. The effect of interaction between rake angle and clearance angle on cutting temperature also appeared to be important. Finally, the optimal parameter combinations of tool geometries for cutting force and cutting temperature are obtained, respectively.
Intelligent Tool Condition Monitoring System Based on Rough Sets and Mathematical Morphology
Authors: Zhang Li , Ji Shi Ming , Xie Yi , Yuan Qiao Ling , Zhang Yin Dong , Yao Z.N.
Published: March 2009

The image of cutting tools provides reliable information regarding the extent of tool wear.
In this paper, we propose the theory of image processing based on rough sets and mathematical
morphology to analyzing the flank faces which are chosen as our monitoring object. First, through
plotting the appropriate subset, the rough sets filter is used to enhancement the image of tool wear.
Then, the mathematical morphology theory is applied to process the translated binary image. Finally,
tool condition monitoring is realized by measuring the area of tool wear. This paper gives the
corresponding monitoring principal and proposes a new algorithm to process the cutting tool image.
The algorithm is also flexible and fast enough to be implemented in real time for online tool wear or
tool condition monitoring.
An Empirical Study of the Relationship between Business Performance Measures and Environmental and Competitive Strategy Variables
Authors: Wang W.B. , Tian Ye Zhuang , Sun H.Y.
Published: March 2009

This paper aims to investigate the relationship among business strategies and business performance in global and local manufacturing companies. The research is based an International Manufacturing Strategy Survey (IMSS2005) of about 700 companies from more than 20 countries. We first proposed a new method to construct a generic measure of business performance from the available performance measures in IMSS. Based on this new measure we developed a simple discriminant analysis to allocate each entry (company in the IMSS) into a particular category of business performance. Of course we performed some statistical tests to confirm the validity of this classification. We then analysed the contribution (importance) of various environmental and competitive variables to each category of the generic business performance in order to identify the most influential variables and notice of their difference among different business performances. This was done intuitively using graphical analysis, but we also carried out statistical tests to confirm that companies at different performance levels do operate at different environments and pay different attentions to competitive strategies. The models we developed are simple but novel and very practical. The results showed significant differences among business performances in terms of influential variables, and we conclude that this method can also be used to analyse other part of the data from the IMSS.
Efficient Algorithms for Calculations of the Maximum Surface Form Errors in Peripheral Milling
Authors: Kang Yong Gang , Wang Zhong Qi , Wu J.J. , Jiang Cheng Yu
Published: March 2009

An efficient flexible iterative algorithm with a general approach is presented for calculations of surface form errors in peripheral milling of thin-walled workpiece. An efficient finite-element model for tool/workpiece is presented to analyze the surface dimensional errors in peripheral milling of aerospace thin-walled workpieces. The efficient flexible iterative algorithm is proposed to calculate the deflections and the maximum surface form errors as contrasted with the rigid iterative algorithm used in the literatures. Meanwhile, some key techniques such as the finite-element modeling of the tool-workpiece system; the determinant algorithm to judge instantaneous immersion boundaries between a cutter element and the workpiece; iterative scheme for the calculations of tool-workpiece deflections considering the former convergence cutting position are developed and the method for calculating the position and magnitude of the maximum surface form errors are developed and presented in detail. The proposed approach is validated and proved to be efficient through comparing the obtained numerical results with the test results.
PCBN Tool Performance Evaluation Based on Image Analysis of Machining Surface Texture
Authors: Wang P. , Liu D.L. , Liu Yi Zhi , Liu Xian Li , Wu Chun Ya
Published: March 2009

The Polycrystalline Cubic Boron Nitride (PCBN) cutting tools has have been developed
for high speed machining in modern automation manufacture. The machining surface roughness is
regarded as an important criterion to assess PCBN cutting tools performance. There are too many
problems in conventional detection method. In order to solve that problem, we present a new way
that is based on image analysis of machining surface texture to assess surface roughness. The new
method is consisted of three steps. It captures surface texture image when machining is finished or
pauses. Firstly, RGB histogram is adopted to analyze image pixel information. This means takes
advantage of histogram technique and provides more pixel distribution information than gray
histogram. Secondly, unsupervised texture segmentation is used based on resonance algorithm.
Thirdly, a new estimation parameter E that is the density of surface contour peak is put forward to
estimate machining surface roughness.
5-Axis Tool Positioning via RFIM Strategy
Authors: Wang Dan , Chen Wu Yi , Wang Rui Qiu
Published: March 2009

A new strategy for 5-axis NC machining called Rotate-For-Intersect Machining (RFIM)
was presented in this paper. The cutter was settled by two cutter contact points and in order to
obtain optimized tool position and orientation, grid point method and bi-section method ware
utilized in searching cutter’s rotate angle and tilt angle. Finally the algorithm was implemented on
UG platform following further development and the effectiveness of the method was validated.
Cutting Parameters Optimization by Using Particle Swarm Optimization (PSO)
Authors: Li Jian Guang , Yao Ying Xue , Gao Dong , Liu Chang Qing , Yuan Zhe Jun
Published: March 2009

Cutting parameters play an essential role in the economics of machining. In this paper, particle swarm optimization (PSO), a novel optimization algorithm for cutting parameters optimization (CPO), was discussed comprehensively. First, the fundamental principle of PSO was introduced; then, the algorithm for PSO application in cutting parameters optimization was developed; thirdly, cutting experiments without and with optimized cutting parameters were conducted to demonstrate the effectiveness of optimization, respectively. The results show that the machining process was improved obviously.
Construction of ASP Platform Based on the Manufacture of Typical Components for the Engineering Machinery
Authors: Gu Li Zhi
Published: March 2009

Briefly reviewed the origin and presence of ASP, elicited the basic requirements of the construction of ASP platform on all-purpose and special needs for enterprises manufacturing the products of engineering machinery. The hierarchy of overall structure for ASP was presented with five layers: client’s layer, representation layer, professional logic layer, integration layer, and resource layer for different functions. Emphasis was focused on the data centers with the representation layer closer to the client’s terminals, the original IT resources stored in the local areas, and important data stored in the secure stations and backup and with standby data centers; on the manufacturing system based on CAD/CAPP/VM and other related techniques; and on the security system with access manipulations, secret keys, ID discriminations and audit tracking. The initial ASP platform has been set up for the medium and small sized enterprises, and was actuated with Rational Rose, UML adopted for the web system, and JavaScript employed for the events, databases, and development of the user’s terminals. Quanhigh Machinery Company was taken as an example in application with four kinds of typical components of engineering machinery.
Analyze of Clamp Rod on Spring Tube Stiffness Measurement
Authors: Wang Hui Feng , Wang Guang Lin
Published: March 2009

It shows the measure principal of spring tube stiffness, analyzes the act of clamp rod in
stiffness measurement of spring tube. Clamp rod is optimized to elevate measurement precision, a
optimized clamp rod is showed. Much test is carried out with the former and the optimization
respectively, the result shows that the stiffness measurement is improved and the design is satisfied
through optimizing the clamp rod.
Dynamic Balance Analysis of Drum-Shape Rotor
Authors: Zhang H.B. , Zhou L. , Yao Ying Xue
Published: March 2009

For rigid rotor that widely applied in gyroscopes, high precision dynamic balance is very
important. The paper introduces a dynamic balance method for drum-shape gyroscope rotor: the
rotor is supported by gas bearing; detecting the displacement of three points on the drum-shape
rotor’s end-plane, obtaining its normal direction. Then according to geometrical relation of
geometric axis and polar inertia axis, the dynamic trace of the rotor can be obtained, and the rotor’s
mass imbalance is calculated. Experiment result shows that the method has high balance accuracy,
particularly suit for high-speed gyroscope rotor whose mass imbalance is small.
Brittle Fracture-Based Experimental Methodology for Microstructure Analysis
Authors: Hoefnagels J.P.M. , Tasan C.C. , Pradelle M. , Geers M.G.D.
Published: March 2009

Metallographic techniques are crucial tools for establishing the connection between
observed mechanical behaviour of metals and the underlying mechanisms in their microstructures.
In this work, we propose a methodology that minimizes deformation and/or modification of the
microstructure during specimen preparation, and provides a 3D representation of the deformed
micromorphology. This methodology involves opening up fractured (tensile test) specimens under
the ductile-to-brittle transition temperature of metals to yield two parts in a brittle manner. The
occurrence of brittle fracture is validated by analyzing the detailed, unaltered microstructure from
SEM characterization and surface profilometry mapping of sets of two parts. It is found that this
technique yields additional valuable information regarding the size and morphology of deformed
grains or nucleation mechanisms of ductile damage. Experiments with a number of different steels
show that the methodology can be applied to sheet of different formability.
Cumulative Damage Evaluation under Fatigue Loading
Authors: Granda Marroquín L.E. , Hernández-Gómez Luis Héctor , Urriolagoitia-Calderón G. , Urriolagoitia-Sosa G. , Merchán-Cruz E.A.
Published: March 2009

The goal of this paper is to present the results obtained from damage evaluation in
automotive axles, which are under torsion fatigue. For this purpose, a Nonlinear Damage Model is
used. The mentioned shafts have to satisfy geometry requirements and their material has to be heat
treated in order to improve their performance. One has to keep in mind that fatigue strength depends
on material properties and geometry. In order to make a precise evaluation of the accumulated
damage, the manufactured shafts were tested. In the first instance, the mechanical properties of the
material were evaluated with static torsion tests. In the next step, the S-N curves were obtained with
torsion fatigue tests. In all these cases, temperature was controlled. Experimental data at different
load levels was gathered with strain gages in conjunction with a data acquisition system. The life
cycle history of each tested shaft was stored and with this experimental evidence, damage curves
were obtained and the cumulative damage of the axle was established. With these damage curves, it
is possible to define the relation between damage rate and life for different stress levels.
Experimental Analysis and Quasi-Static Numerical Idealization of Dynamic Stresses on a Heavy Truck Chassis Frame Assembly
Authors: Chinnaraj K. , Sathya Prasad M. , Lakshmana Rao C.
Published: March 2009

The current trend in automotive design is to optimize components for weight. To achieve
this, automotive designers need to have complete understanding of various stresses prevalent in
different areas of the component. The chassis frame assembly of a heavy truck used for long
distance goods hauling application is chosen for this investigation and dynamic stress-strain
response of the component due to braking and cornering maneuvers are experimentally measured
and reported. A quasi-static approach that approximates the dynamic maneuvers into number of
small processes having static equilibriums is followed to carry out the numerical simulation,
approximating the dynamic behavior of frame rail assembly during cornering and braking. With the
help of commercial finite element package ANSYS, the quasi-static numerical simulations are
carried out and compared with experimental results. This study helps in understanding prevailing
stresses in truck frame rails especially during cornering and braking maneuvers and brings out all
geometric locations that may be potential failure initiation locations. This study makes a case for
further investigation on the effects of residual and assembly stresses on frame rails.
A Principal Component Analysis of Acoustic Emission Signals from a Landing Gear Component
Authors: Pullin Rhys , Eaton Mark J. , Hensman James J. , Holford Karen M. , Worden Keith , Evans S.L.
Published: March 2009

This work forms part of a larger investigation into fracture detection using acoustic
emission (AE) during landing gear airworthiness testing. It focuses on the use of principal
component analysis (PCA) to differentiate between fracture signals and high levels of background
noise. An artificial acoustic emission (AE) fracture source was developed and additionally five
sources were used to generate differing AE signals. Signals were recorded from all six artificial
sources in a real landing gear component subject to no load. Further to this, artificial fracture signals
were recorded in the same component under airworthiness test load conditions. Principal component
analysis (PCA) was used to automatically differentiate between AE signals from different source
types. Furthermore, successful separation of artificial fracture signals from a very high level of
background noise was achieved. The presence of a load was observed to affect the ultrasonic
propagation of AE signals.
Design of a Multi-Axial Test Specimen for Fretting Fatigue in Splined Couplings
Authors: Wavish P.M. , McColl Ian R. , Leen Sean B.
Published: March 2009

This paper describes the conceptual, embodiment and detailed design of a representative test specimen to mimic fretting variables in aero-engine splined couplings. A fretting bridge design was chosen for the multi-axial representative specimen from a set of four concepts evaluated. The test specimen was intended to facilitate more rapid testing for design against fretting fatigue and wear in the complex contact geometry of the spline coupling.
An Inverse Procedure for Determining the Material Constants of Isotropic Square Plates by Impulse Excitation of Vibration
Authors: Alfano Marco , Pagnotta Leonardo
Published: March 2009

The paper presents a procedure whereby the Poisson’s ratio and dynamic Young’s modulus of isotropic and homogeneous materials are determined using two of the first four frequencies of natural vibration in thin square plates. The procedure is based on suitable approximate relationships relating the resonant frequencies to the elastic constants of the material. These relations were derived from an extensive series of numerical analysis carried out by a finite element code. To measure the fundamental resonant frequencies, inexpensive computerized equipment is proposed. The procedure has been validated on Carbon Steel specimens.
Experimental Determination of SEA Parameters of Stiffened Cylindrical Shell Structure
Authors: Ramachandran P. , Narayanan S.
Published: March 2009

A method to predict the modal density and radiation efficiency of orthogonally stiffened cylindrical shell is presented in this paper. The modal density is derived using energy method from the undamped natural frequencies of stiffened shell by treating the stiffeners as discrete elements. The band averaged radiation efficiency is estimated by categorizing the structural modes into acoustically fast and acoustically slow modes. The predicted parameters are compared with experimental results using laser vibrometer measurements. Phase-roll off has been observed in laser vibrometer measurements for which a correction procedure is applied. This prediction method can be easily extended to shells with stiffeners having different size, orientation etc.
Measurement and Analysis of Impact Test Data for X100 Pipeline Steel
Authors: Hashemi S.H. , Howard I.C. , Yates J.R. , Andrews R.M.
Published: March 2009

Charpy upper shelf energy is widely used as a fracture controlling parameter to estimate the crack arrest/propagation performance of gas transportation pipeline steels. The measurement of this fracture criterion particularly for modern steels and its apportion into different components, i.e. fracture and non-related fracture energy, are of great importance for pipeline engineers. This paper presents the results of instrumented Charpy impact experiments on high-grade pipeline steel of grade X100. First, the instrumentation technique including the design and implementation of a strain gauge load-cell and the details of the data-recording scheme are reviewed. Next, the experimental data obtained from the Charpy impact machine so instrumented are presented and discussed. These include the test data from full and sub-sized Charpy V-notched specimens. The instrumented Charpy machine was able to capture the load history in full during the fracture process of the test specimens resulting in a smooth load-time response. This eliminated the need for filtering used in similar test techniques. From the recorded test data the hammer displacement, impact velocity and fracture energy were numerically calculated.
The results showed that there was a significant drop in hammer velocity during the impact event. This resulted in a change in the fracture mode from dynamic to quasi-static which was more appreciable for full-size Charpy test samples. As a result, sub-sized specimens might be preferable for impact testing of this steel in order to guarantee the conditions of dynamic crack propagation in the specimen ligament. Accurate analysis of the instrumented impact test data showed that the ratio of crack initiation energy to propagation energy was around 30% for the X100 steel. It can be concluded that in impact testing of high-grade pipeline steel a significant portion of overall fracture energy is consumed in non-related fracture processes. This high fracture initiation energy should be accounted for if the current failure models are going to be used for toughness assessment of highstrength low-alloy gas pipeline steels.
Elastic-Plastic Stress Analyses by Digital Image Correlation and Nonlinear Hybrid Method
Authors: Machida Kenji
Published: March 2009

In previous studies, the elastic stress field near the crack tip was investigated by digital image correlation and the 2-D intelligent hybrid method. In this study, the 2-D nonlinear hybrid method was developed to analyze the elastic-plastic singular stress field near the crack tip from the displacement data obtained by digital image correlation. Then, the 2-D nonlinear hybrid method was carried out to evaluate stress, strain and J integral. The 3-D elastic-plastic finite element method was conducted on the same specimen as the experiment, and the validity of this approach was discussed from the comparison of the experiment and 3-D finite element method.
Design of an Ultrasonic Blade for Cutting Bone
Authors: MacBeath Alan , Cardoni Andrea , Lucas Margaret
Published: March 2009

Damaging temperature effects observed during ultrasonic cutting operations are typically a result of friction between the vibrating blade and material, and combustion of debris. In order to prevent the high temperatures causing damage, the ultrasonic blade has to cut with a sufficient speed. This can be achieved either by applying a relatively high static load or by increasing the working vibration amplitude of the cutting edge, however, the result can be poor operational control and exceeding the fatigue limit of the blade, respectively. In this paper, the effect of blade tip profile is considered, particularly with reference to the influence of the cutting edge contact area on temperature under different static loading conditions. Titanium blades, with different cutting edge profiles are tested in a series of experiments that monitor cutting speed, static load, temperature around the cut site, and vibration amplitude at the cutting edge. The blades are tested cutting bovine femur and artificial bone material, and the cut surfaces are examined for signs of damage after each test. The experimental data reveal that blades with a small cutting edge contact area cut at a lower temperature, and that signs of thermal damage are less evident.
Studies on Misalignment in Coupled Rotors
Authors: Lees A.W.
Published: March 2009

Misalignment of multi-bearing rotor systems is one of the most common fault conditions
yet it is still not fully understood. There are numerous (and sometimes confusing) accounts in the
literature asserting the presence of harmonics in the vibration signal, but no quantitative
descriptions are offered. Harmonics may arise, of course, from the nonlinearities in fluid film
journal bearings or from the kinematics of flexible couplings, but in this paper only rigidly coupled
rotors mounted on idealised linear bearings. It is shown that even for this case, excitation at twice
synchronous speed is developed and an expression for the magnitude and phase of the response is
derived. Several examples are then studied to give some insight into the magnitude of these
harmonic terms which can arise. It is argued that it is precisely because the harmonic terms can
arise from diverse sources, a full description of the phenomena has proved somewhat elusive.
A brief discussion of the type of rig required to validate the model is given. There is a need to
separate the phenomena discussed here from the nonlinearities found in real machines. Some
features of the new facility are described.
Flexural Testing of Composite Sandwich Structures with Digital Speckle Photogrammetry
Authors: Fergusson Alexander D. , Puri Amit , Morris Andrew , Dear John P.
Published: March 2009

Composite sandwich structures are finding increasingly widespread use in fields ranging
from aerospace and wind turbines to sports applications such as skis and surfboards. The high
specific stiffness that composite sandwich structures can provide lends them well to these
applications. However, the operational environment of these structures is frequently aggressive and
often results in damage during service. The extent and effect of damage incurred is an important
factor in the design and maintenance of composite sandwich structures. Failure of an individual
component can be catastrophic for the rest of the structure.
The purpose of this investigation was, firstly, to ascertain whether DSP was a viable technique
for determining strain fields within composite sandwich structures. Secondly, to determine whether
four point flexure would give rise to pure flexure between the central rollers, and if not, to
understand what load conditions were present. This investigation was also carried out with a view
to extend the investigation into the effect of defects on composite sandwich structures manufactured
by RIFT.
The grounds for selection of composite sandwich structures normally lie in their flexural
performance. Reliable and accurate quantitative testing methods for evaluating the flexural
performance of sandwich panels are needed if composite sandwich structures are to be used safely
and effectively. In addition, methods to determine the effect of damage and defects on flexural
behaviour of sandwich structures is particularly important for designing the repair and maintenance
regimes of composite sandwich components.
Monitoring High Temperature Steam Pipes Using Optical Strain Measurement Techniques
Authors: Morris Andrew , Dear John P. , Kourmpetis Miltiadis
Published: March 2009

Optical strain measurement techniques have been extensively developed in recent years
in order to cope in various environments. Power stations and wind turbine blades can provide
challenging environments for the use of a measurement technique. There are, however, many
installation problems to be overcome. For example, there is the need to have regard for the hostile
environment in steam generating plant and the demanding conditions to which wind turbine blades
are subjected.
Ideally the outputs from individual sensors would be used for continuous remote monitoring.
However, measurements can also be useful each time the plant is shut down during a plant outage;
which would be used to complement data from existing proven rugged monitoring methods.
This paper addresses the monitoring of pressurized steam pipes as to their micro-strain growth
related to time in service. This paper presents the progress made in the developing of a ruggedised
digital speckle ‘sensor’ and associated image capture system. The effect of subsurface defects in the
strain distribution is examined.
Towards the Modelling of Fretting Wear and Fatigue Interaction in Spline Couplings
Authors: Ding Jian , Madge J. , Leen Sean B. , Williams Edward J.
Published: March 2009

The prediction of fretting wear and fretting fatigue is a significant issue for the design of
high-performance aeroengine spline couplings, due to the potential for slip between the highlyloaded
spline teeth under cyclic loads. The work reported here builds on previous work on simpler
(Hertzian) laboratory test configurations to take a step towards a unified fretting wear and fatigue
modelling approach, which considers the evolution of contact geometry with material removal and
consequently the changes in fatigue-pertinent subsurface stresses. The approach calculates the local
wear, that it is the wear at each contact node, as a function of local contact pressure and local slip.
The influence of wear damage on fretting fatigue behaviour is quantitatively assessed by computing
the change of a shear strain based fatigue damage parameter, i.e. the critical-plane Fatemi-Socie
parameter. The application of the simulation tool to the complex geometry of a helical spline
coupling is discussed.
Effect of Contact Interaction on the Stress Intensity Factors for a Crack under Harmonic Loading
Authors: Menshykov Oleksandr , Guz I.A.
Published: March 2009

This paper concerns fracture dynamic problems for elastic cracked solids with allowance
for crack faces contact interaction. The contact problem for a penny-shaped crack with an initial
opening under normally incident tension-compression wave is solved by the method of boundary
integral equations. The solution is compared with those obtained without allowance for crack faces
contact interaction for various values of the initial opening.
The Effect of Hygrothermal Composite Patch on the Fracture of Reinforced Crack under Mixed-Mode Loading
Authors: Hashemi R. , Ayatollahi Majid R.
Published: March 2009

The mechanical properties of composite laminates play a key role in the success of
composite reinforcement method, but various investigations suggest that the stiffness of epoxybased
composites is sensitive to the variation of moisture ratio and temperature of the working
environment. The aim in this research is to characterize the effect of hygrothermal aged composite
patch on the strength of repaired cracks, under mixed mode I/II conditions. For this purpose a
reinforced sheet, i.e. a crack fastener hole specimen is examined by using a finite element
simulation. The crack tip parameters and fracture characteristics of repaired cracks are determined
as a function of the total amount of moisture inside the composite patch. The results of this study
show that the performance of composite reinforcement technique depends on the amount of water
absorption within the bonded patches.
Damping Measurement of Bending Vibration in Alpine Skis: An Improvement of Standard ISO 6267
Authors: Fanti Giulio , Basso R. , Montauti V.
Published: March 2009

The ISO 6267 standard defines a damping measuring method in terms of the half-time of
the vibration of clamped alpine skis that is mainly related to the first vibration mode only. By means
of the experimental test done in laboratory, it is shown that this method is not able to completely
characterize the damping of the skis that depends on the vibration mode considered. For example in
the case a ski sample, damping ratio varies from 0.45%±0.05% of the first mode to 2.1%±0.1% of
the fourth one.
The experimental test done on ski tracks by means of piezo-accelerometers placed on the skis
running at speed of 12.5 m/s showed that the skis vibrate according to a combination of at least the
first 4 vibration modes and that the snow better excites frequencies greater than the first one.
As the excitation frequencies on the skis during the descent are much higher than the first natural
frequency of the ski, it appears not correct to hypothesize that only the damping coefficient relative
to the first natural frequency is representative of the ski vibrations.
To improve the UNI ISO 6267 standard, a new method based on the Fourier Transform filtering
to separate the time history into the vibration components is proposed for the characterization of the
ski damping that is variable with its natural modes.
Natural Frequencies and Mode Shapes of Deterministic and Stochastic Non-Homogeneous Rods
Authors: Nachum S. , Altus E.
Published: March 2009

In this study the natural frequencies and mode shapes of the kth order of nonhomogeneous
(deterministic and stochastic) rods are found. The solution is based on the functional
perturbation method (FPM). The natural frequency and mode shape of the kth order is found
analytically to any desired degree of accuracy. In the deterministic it is shown that the FPM
accuracy range for the frequency ω and the mode shape is less then 1%. The stochastic case
demonstrates the power of this method. The material and geometrical properties will be considered
as statistically homogeneous random field with exponential two-point correlation. It is shown that
the accuracy depends on the stochastic information used, the correlation distance (roughly the
“grain size”), and whether we are interested in the properties of ω or ω2.
Non-Linear Modal Interactions in a Suspension Rope System with Time-Varying Length
Authors: Salamaliki-Simpson Rodanthi , Kaczmarczyk Stefan , Picton Phil , Turner Scott
Published: March 2009

This paper focuses on the investigation of the autoparametric coupling effects and modal
interactions in a suspension rope system with a time varying length. Equations of motion of a
multi-degree-of-freedom discrete, non-stationary and non-linear model are presented and are used
to analyze the dynamic response of an elevator suspension rope system under resonance conditions.
The equations of motion involve quadratic and cubic non-linear terms which are responsible for the
modal interaction between the lateral and longitudinal oscillations of the rope and the car motions.
The model takes into account the periodic excitations caused by motion of the host structure. The
results confirm that adverse responses may arise and internal autoparametric resonance phenomena
may occur.
Application of Modal Analysis to Cylinder Structure Based on Random Vibration Test
Authors: Li C. , Hu S. , Li J.
Published: March 2009

This paper presents the application of modal analysis and parameter identification
using data of random vibration test to a cylinder structure. It is deduced that the impulse
response function can be substituted by the cross-correlation function computed directly
from the response-only data based on the white noise excitation or broadband input. So the
modal parameter identification can be done by the least squares complex exponential
(LSCE) method. And the modal parameters are obtained from the random vibration test data
by the complex exponential method. Compared with the results of traditional modal test, the
results of random vibration test are proved to be correct, and also the feasibility of this idea
is proved well.
A Wavelet Approach for the Analysis of Bending Waves in a Beam on Viscoelastic Random Foundation
Authors: Koziol Piotr , Mares Cristinel , Esat Ibrahim
Published: March 2009

This paper deals with the mathematical model of dynamic behaviour of a beam resting
on viscoelastic random foundation for which the modulus of subgrade reaction is assumed to be a
homogeneous random function of the space variable. An approximate analytical solution for the
fourth-order differential equation with random parameters is obtained in the case of a
∞
C -class
correlation function. This higher order regularity of correlation function implies the regularity of
associated stochastic function [1] in the sense of the mean-square analysis [2]. The numerical results
for the average displacement have been obtained by using Bourret’s approximation method. A
special method of finding inverse Laplace transform based on the wavelet theory is adopted and
used in the numerical examples.
On the Problem for Damage Detection of Vibrating Cracked Plates
Authors: Trendafilova Irina , Manoach Emil , Cartmell Matthew P. , Krawczuk Marek , Ostachowicz Wiesław M. , Palacz Magdalena
Published: March 2009

This work was motivated by the recent NATO funded research on preventing disasters
from collapse and improving the safety of aircraft structures. It considers the problem for vibrationbased
damage detection in aircraft panels modelled as isotropic plates. The explored method does
not use any assumptions of model or linearity, it is simply based on pure signal analysis of the
vibration response of plates. FE modelling is used to model the plate’s dynamic response in its
intact and in its damaged state. The signals obtained are analysed using multivariate analysis applied
in the measured frequency domain. This reduces the data dimensionality and is expected to have a
clustering effect. At this stage the measured data is transformed into features – new variables- which
have smaller dimension than the initial ones and make the categories more distinguishable. Then a
very simple pattern recognition (PR) method is applied to discriminate between the two categories
of data -data coming from the undamaged plate and data coming from the damaged plate. This is the
second stage when the obtained features are used for the actual recognition between the defined
categories. The paper suggests the use of the Karhunen-Loeve transform in order to extract features
from the measured frequency response functions of the plate. When the data dimensionality is
brought down to two the response of the plate can be visualised. The clustering effect on the
features coming from undamaged plate and those from the damaged is obvious.
Force Appropriation for Nonlinear Systems (FANS) Using Optimisation Methods
Authors: Hickey D. , Worden Keith , Wright Jan R. , Cooper J.E.
Published: March 2009

Normal mode force appropriation is a method of physically exciting and measuring
the undamped natural frequencies and normal mode shapes of a structure. Traditionally used
in the aerospace industry for ground vibration testing, it is capable of accurate normal mode
estimates. The method attempts to determine multi-point force vectors that will induce single
mode behaviour, thus allowing each mode to be viewed in isolation. However it fails to tackle
changing dynamic response with forcing level of excitation in nonlinear systems. The method
of Force Appropriation for Nonlinear Systems or FANS, produces a special appropriated force
vector resulting in nonlinear response. The structure responds dominantly in the target linear
mode shape permitting the direct nonlinear characteristics of that mode to be identified in the
absence of cross coupling effects.
Proposals for Controlling Flexible Rotor Vibrations by Means of an Antagonistic SMA/Composite Smart Bearing
Authors: Inman Daniel J. , Cartmell Matthew P. , Lees A.W. , Leize Th. , Atepor L.
Published: March 2009

Recent EPSRC funded research at Glasgow University, Swansea University, and Virginia
Polytechnic and State University, and collaborative work with the Karlsruhe University of Applied
Sciences, on the application of shape memory alloy (SMA) elements integrated within glass epoxy
composite plates and shells is currently leading to the design of a novel smart bearing based on the
principle of antagonistic action. In this system a ball bearing is fitted halfway down a glass epoxy
composite tube, entering through one end of the tube. The tube has both ends rigidly built in to the
support frame. The tube is divided into two regions, one on each side of the centrally located
bearing. SMA strips are bonded in two independent sets of four, each set running axially along half
the length of the tube and separated by 90 º around the tube. The four strips in each set are
electrically connected in series to a high current power supply that can be switched in or out, and
the current set, as required. This provides a convenient and fast way of heating each set of SMA
strips through the martensite-to-austenite transformation temperature, and provides a significant
axial contraction load on the tube in either direction. Previous FE analysis has provided predictions
for converting an axial contraction load into useful stiffening of the structure in the radial and hoop
directions. This introduces the potential for modification of the dynamic performance of the
flexible rotor. In addition to separate heating each half of the active bearing has its own
independent forced-air cooling system. Previous work by one of the authors, and others, has shown
that a single SMA/composite active bearing can be very effective in both altering the natural
frequency of the fundamental whirl mode as well as the modal amplitude. The drawback with that
design has been the disparity in the time constant between the relatively fast heating phase and the
much slower cooling phase which is reliant on forced air, or some other form of cooling. This form
of design means that the cooling phase of one half, still using forced air, is significantly assisted by
switching the other half into its heating phase, and vice versa, thereby equalising the time constants,
and giving a faster push-pull load on the centrally located bearing; a loading which is termed
‘antagonistic’ in this paper. The experimental system is discussed in terms of potential performance
and control issues.
Stresses in Ultrasonically Assisted Turning
Authors: Ahmed N. , Mitrofanov A.V. , Babitsky Vladimir I. , Silberschmidt Vadim V.
Published: March 2009

Ultrasonically assisted turning (UAT) is a novel material-processing technology, where
high frequency vibration (frequency f ≈ 20kHz, amplitude a ≈15μm) is superimposed on the
movement of the cutting tool. Advantages of UAT have been demonstrated for a broad spectrum of
applications. Compared to conventional turning (CT), this technique allows significant
improvements in processing intractable materials, such as high-strength aerospace alloys,
composites and ceramics. Superimposed ultrasonic vibration yields a noticeable decrease in cutting
forces, as well as a superior surface finish. A vibro-impact interaction between the tool and
workpiece in UAT in the process of continuous chip formation leads to a dynamically changing
stress distribution in the process zone as compared to the quasistatic one in CT. The paper presents
a three-dimensional, fully thermomechanically coupled computational model of UAT incorporating
a non-linear elasto-plastic material model with strain-rate sensitivity and contact interaction with
friction at the chip–tool interface. 3D stress distributions in the cutting region are analysed for a
representative cycle of ultrasonic vibration. The dependence of various process parameters, such as
shear stresses and cutting forces on vibration frequency and amplitude is also studied.
Effects of Laser Welding Conditions on Toughness of Dissimilar Welded Components
Authors: Anawa E.M. , Olabi Abdul Ghani
Published: March 2009

Welding dissimilar materials become inevitable in engineering industries. There are
many issues/problems associated with the welding of dissimilar materials, related to the welding
process and its parameters. The current work investigates the effect of laser welding conditions on
the toughness of dissimilar welded components.
In this study, CO2 laser welding has been successfully applied for joining 316 stainless steel with
low carbon steel (F/A). Design of experiment techniques has been used for different effective
welding parameters (laser power, welding speed, and focus position) to optimize the dissimilar F/A
joints in terms of its mechanical properties.
Taguchi approach was applied to optimize the welding parameters. Three factors with five levels
each (L-25) were employed in these models. Impact strength was measured at room temperature by
using the universal pendulum impact tester. The results were compared with the impact strength of
the base material. The results were analysed using ANOVA and S/N ratio for optimal parameters
combination. It is evident that Taguchi approach has decreased the number of experiments without
negative effects on the result.
Application of Generalized Differential Quadrature Method to the Bending of Thick Laminated Plates with Various Boundary Conditions
Authors: Aghdam Mohammad Mohammadi , Farahani M.R.N. , Dashty M. , Rezaei Niya S.M.
Published: March 2009

Bending analysis of thick laminated rectangular plates with various boundary conditions
is presented using Generalized Differential Quadrature (GDQ) method. Based on the Reissner first
order shear deformation theory, the governing equations include a system of eight first order partial
differential equations in terms of unknown displacements, forces and moments. Presence of all plate
variables in the governing equations provide a simple procedure to satisfy different boundary
condition during application of GDQ method to obtain accurate results with relatively small number
of grid points even for plates with free edges .Illustrative examples including various combinations
of clamped, simply supported and free boundary condition are given to demonstrate the accuracy
and convergence of the presented GDQ technique. Results are compared with other analytical and
finite element predictions and show reasonably good agreement.
Decoupling the Equations of Isospectral Flow
Authors: Garvey Seamus D. , Van Eetvelt Peter , Prells U.
Published: March 2009

Three (m × n) matrices {K, D, M} represent a second-order system in the form
(K + Dλ+ Mλ2). If m = n, system eigenvalues are defined as the values of λ for which
det(K + Dλ+ Mλ2) = 0. If {K, D, M} are continuous functions of a real scalar parameter, σ,
eigenvalues and dimensions of the associated eigenspaces remain constant if and only if the rates of
change of {K, D, M} obey certain ODEs called the isospectral flow equations. The integration of
these matrix differential equations is of interest here. This paper explains the motivation behind this
work in terms of vibrating systems and it reports two related hypotheses concerning how the
solutions to these equations may be decoupled. Work underway towards proving and using these
hypotheses is presented. No existing known solutions allow this decoupling in general.
A Study of Residual Stress Effects due to Adhesive Bonding of MEMS Components
Authors: Sadaba I. , Fox Colin H.J. , McWilliam Stewart
Published: March 2009

Residual stress effects in MEMS wafer adhesive bonding were investigated. A waferlevel
finite element (FE) modelling approach was used, which accounted for wafer configuration
and allowed the deformation of individual devices across a wafer to be considered. A specific test
was carried out to determine the adhesive’s viscoelastic response, through an effective timedependent
Young`s modulus, so that initial and longer-term post-curing responses could be
estimated. These results are compared with predictions based on modulus values obtained from
Dynamic Mechanical Analysis (DMA) testing. The predicted wafer deformations are compared
with optical surface profile measurements of actual specimens. Initial response predictions using the
effective modulus show excellent agreement with measurements, while the DMA modulus gives a
significant underestimate. On the other hand, difficulty was found in modelling long-term
relaxation, due to non-linear mechanisms such as polymer “ageing” which are harder to model.