scholarly journals Biodynamic Response of Femur Bone

2020 ◽  
Vol 9 (5) ◽  
pp. 1406-1412
Keyword(s):  
Boundary Conditions ◽  
Research Work ◽  
Mode Shapes ◽  
Future Research ◽  
Strength Analysis ◽  
Different Boundary Conditions ◽  
Femur Bone ◽  
Surgical Implants ◽  
Research Problems ◽  
Fracture Study

The main objective of this paper is to study the development of research work performed for femur bone. A broad literature survey from 1980 to 2019 was studied. It was observed that researcher had performed modal analysis, strength analysis and fracture study of femur bone in previous study. The natural frequencies were determined and different mode shapes were studied. The bone materials and different boundary conditions of previous study were noted and future research problems was identified. In conclusion from previous studies it was noted that there is lot of scope to perform study on femur bone. These studies will be related to fracture identification, healing of femur bone and advanced strength analysis for varying bone size using different boundary conditions. For surgical implants few new materials are identified that can be used for future study.

scholarly journals In-Plane free Vibration Analysis of an Annular Disk with Point Elastic Support

2011 ◽  
Vol 18 (4) ◽  
pp. 627-640 ◽  
Author(s):  
S. Bashmal ◽  
R. Bhat ◽  
S. Rakheja
Keyword(s):  
Boundary Conditions ◽  
Orthogonal Polynomials ◽  
Ritz Method ◽  
Free Vibration Analysis ◽  
Free Vibrations ◽  
Outer Edge ◽  
Mode Shapes ◽  
Annular Disk ◽  
Different Boundary Conditions ◽  
Boundary Characteristic

In-plane free vibrations of an elastic and isotropic annular disk with elastic constraints at the inner and outer boundaries, which are applied either along the entire periphery of the disk or at a point are investigated. The boundary characteristic orthogonal polynomials are employed in the Rayleigh-Ritz method to obtain the frequency parameters and the associated mode shapes. Boundary characteristic orthogonal polynomials are generated for the free boundary conditions of the disk while artificial springs are used to account for different boundary conditions. The frequency parameters for different boundary conditions of the outer edge are evaluated and compared with those available in the published studies and computed from a finite element model. The computed mode shapes are presented for a disk clamped at the inner edge and point supported at the outer edge to illustrate the free in-plane vibration behavior of the disk. Results show that addition of point clamped support causes some of the higher modes to split into two different frequencies with different mode shapes.

scholarly journals Vibration analysis of carbon nanotubes-based zeptogram masses sensors and taking into account their rotatory inertia

2018 ◽  
Vol 149 ◽  
pp. 02087 ◽  
Author(s):  
A. Azrar ◽  
L. Azrar ◽  
A. A. Aljinaidi
Keyword(s):  
Carbon Nanotubes ◽  
Boundary Conditions ◽  
Methodological Approach ◽  
Nonlocal Parameter ◽  
Research Work ◽  
Mode Shapes ◽  
Attached Mass ◽  
Rotatory Inertia ◽  
Mass Sensors ◽  
Walled Carbon Nanotubes

In this research work, the transverse vibration behaviour of single-walled carbon nanotubes (SCNT) based mass sensors is studied using the Timoshenko beam and nonlocal elasticity theories. The nonlocal constitutive equations are used in the formulations and the CNT with different lengths, attached mass (viruses and bacteria) and the general boundary conditions are considered. The dimensionless frequencies and associated modes are obtained for one and two attached masses and different boundary conditions. The effects of transverse shear deformation and rotatory inertia, nonlocal parameter, length of the carbon nanotubes, and attached mass and its location are investigated in detail for each considered problem. The relationship between the frequencies and mode shapes of the sensor and the attached zeptogramme masses are obtained. The sensing devices for biological objects including viruses and bacteria can be elaborated based on the developed sensitivity and frequency shift methodological approach.

Effect of the Boundary Conditions on the Dynamic Behaviours of Subsea Free-Spanning Pipelines

2018 ◽  
Vol Vol 160 (A2) ◽  
Author(s):  
T T Li ◽  
C An ◽  
M L Duan ◽  
H Huang ◽  
W Liang
Keyword(s):  
Boundary Conditions ◽  
Structural Equation ◽  
Eigenvalue Problems ◽  
Integral Transform ◽  
Cross Flow ◽  
Interaction Model ◽  
Accurate Solution ◽  
Mode Shapes ◽  
Different Boundary Conditions ◽  
The Cross

This paper establishes a fast and accurate solution of the dynamic behaviours of subsea free-spanning pipelines under four different boundary conditions, based on GITT - the generalised integral transform technique. The fluid-structure interaction model is proposed by combining a linear structural equation and a non-linear distributed wake oscillator model, which simulates the effect of external current acting on the pipeline. The eigenvalue problems for the cross-flow vibration of the free-spanning submarine pipeline conveying internal fluid for four different boundary conditions are examined. The solution method of the natural frequency based on GITT is proposed. The explicit analytical formulae for the cross-flow displacement of the pipeline free span are derived, and the mode shapes and dynamic behaviours of the pipeline free span are discussed with different boundary conditions. The methodology and results in this paper can also expand to solving even more complicated boundary-value problems.

Standard-Based Wireless Mesh Networks

2007 ◽  
pp. 921-927
Author(s):  
M. Peng
Keyword(s):  
Wireless Mesh Networks ◽  
Packet Scheduling ◽  
Mesh Networks ◽  
Research Work ◽  
Ieee 802.16 ◽  
Future Research ◽  
Medium Access ◽  
Wireless Routing ◽  
Wireless Mesh ◽  
Research Problems

This article introduces a functional architecture supporting the wireless mesh networks for the IEEE 802.16 standard. Three essential techniques—collision avoiding, packet scheduling, and wireless routing—are intensively presented. Based on the mesh extension of the IEEE 802.16 medium access control (MAC) layer protocol and the relay-based characteristic of WMNs, the algorithms concerning those three essential techniques are briefly reviewed. The suitable algorithms for collision avoiding and packet scheduling mechanisms are analyzed. Meanwhile, the wireless routing algorithm for the proposal architecture is discussed. The future research work is presented and the research problems are focused.

Spread Spectrum Watermarking

2010 ◽  
pp. 455-485
Author(s):  
Santi P. Maity
Keyword(s):  
Real Time ◽  
Spread Spectrum ◽  
Hardware Implementation ◽  
High Reliability ◽  
Research Work ◽  
Hardware Architecture ◽  
Future Research ◽  
Hardware Realization ◽  
Field Programmable ◽  
Research Problems

Spread spectrum (SS) watermarking has proven to be efficient, robust and cryptographically secure. Each bit of watermark information is embedded over wide spectrum of the host signal based on spectrum spreading concept of SS modulation in digital communication and can easily be integrated with many existing data transmission scheme. This has made SS watermarking method more attractive during recent times for many non-conventional applications such as broadcast monitoring, security in communication, authentication and blind assessment of quality of services (QoS) for multimedia signals in mobile radio network. These applications essentially demand development of low cost algorithms so that they can be implemented on real time system through hardware realization. Hardware realization offers advantages over software realization in terms of less area, low execution time, low power, real-time performance, high reliability and also ease of integration with existing consumer electronics devices. This chapter first presents a brief review on hardware implementation of digital watermarking algorithms, followed by development of hardware architecture for spatial domain and fast Walsh transform (FWT) domain SS watermark system design using field programmable gate array (FPGA). A brief sketch on hardware implementation for biorthogonal wavelet based Hilbert transform is also shown that may be extended to design SS watermarking based on the concept of two previous architectures. Few challenges for hardware design of watermarking algorithms are then mentioned with an objective to give an idea how to develop watermarking algorithms so that it can be implemented on hardware. The chapter ends with few open research problems on hardware architecture as scope of future research work.

An exact solution for free vibration of thin functionally graded rectangular plates

2010 ◽  
Vol 225 (3) ◽  
pp. 526-536 ◽  
Author(s):  
A Hasani Baferani ◽  
A R Saidi ◽  
E Jomehzadeh
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Natural Frequencies ◽  
Equations Of Motion ◽  
Vibration Characteristics ◽  
Functionally Graded ◽  
Mode Shapes ◽  
Rectangular Plates ◽  
Functionally Graded Plates ◽  
Different Boundary Conditions

The aim of this article is to find an exact analytical solution for free vibration characteristics of thin functionally graded rectangular plates with different boundary conditions. The governing equations of motion are obtained based on the classical plate theory. Using an analytical method, three partial differential equations of motion are reformulated into two new decoupled equations. Based on the Navier solution, a closed-form solution is presented for natural frequencies of functionally graded simply supported rectangular plates. Then, considering Levy-type solution, natural frequencies of functionally graded plates are presented for various boundary conditions. Three mode shapes of a functionally graded rectangular plate are also presented for different boundary conditions. In addition, the effects of aspect ratio, thickness—length ratio, power law index, and boundary conditions on the vibration characteristics of functionally graded rectangular plates are discussed in details. Finally, it has been shown that the effects of in-plane displacements on natural frequencies of functionally graded plates under different boundary conditions have been studied.

scholarly journals Residual Force Method for damage identification in a laminated composite plate with different boundary conditions

2021 ◽  
Vol 16 (59) ◽  
pp. 35-48
Author(s):  
Amar Behtani ◽  
Samir Tiachacht ◽  
Tawfiq Khatir ◽  
Samir Khatir ◽  
Magd Abdel Wahab ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Composite Plate ◽  
Damage Identification ◽  
Laminated Composite ◽  
Mode Shapes ◽  
Estimation Accuracy ◽  
Laminated Composite Plate ◽  
Different Boundary Conditions ◽  
Damage Indicators ◽  
Residual Force

The strongest point about damage identification based on the dynamic measurements, is the ability perform structural health evaluation globally. Researchers in the last few years payed more attention to damage indicators based on modal analysis using either frequencies, mode shapes, or Frequency Response Functions (FRFs). This paper presents a new application of damage identification in a cross-ply (0°/90°/0°) laminated composite plate based on Force Residual Method (FRM) damage indicator. Considering single and multiple damages with different damage levels. As well as investigating the SSSS and CCCC boundary conditions effect on the estimation accuracy. Moreover, a white Gaussian noise is introduced to test the challenge the technique. The results show that the suggested FRM indicator provides accurate results under different boundary conditions. Favouring the SSSS boundary condition than the CCCC for 3% noise.

EFFECT OF THE BOUNDARY CONDITIONS ON THE DYNAMIC BEHAVIOURS OF SUBSEA FREE-SPANNING PIPELINES

2021 ◽  
Vol 160 (A2) ◽  
Author(s):  
T T Li ◽  
C An ◽  
M L Duan ◽  
H Huang ◽  
W Liang
Keyword(s):  
Boundary Conditions ◽  
Structural Equation ◽  
Eigenvalue Problems ◽  
Integral Transform ◽  
Cross Flow ◽  
Interaction Model ◽  
Accurate Solution ◽  
Mode Shapes ◽  
Different Boundary Conditions ◽  
The Cross

This paper establishes a fast and accurate solution of the dynamic behaviours of subsea free-spanning pipelines under four different boundary conditions, based on GITT - the generalised integral transform technique. The fluid-structure interaction model is proposed by combining a linear structural equation and a non-linear distributed wake oscillator model, which simulates the effect of external current acting on the pipeline. The eigenvalue problems for the cross-flow vibration of the free-spanning submarine pipeline conveying internal fluid for four different boundary conditions are examined. The solution method of the natural frequency based on GITT is proposed. The explicit analytical formulae for the cross-flow displacement of the pipeline free span are derived, and the mode shapes and dynamic behaviours of the pipeline free span are discussed with different boundary conditions. The methodology and results in this paper can also expand to solving even more complicated boundary-value problems.

A Spectral-Tchebychev Solution for Three-Dimensional Vibrations of Parallelepipeds Under Mixed Boundary Conditions

2012 ◽  
Vol 79 (5) ◽  
Author(s):  
Sinan Filiz ◽  
Bekir Bediz ◽  
L. A. Romero ◽  
O. Burak Ozdoganlar
Keyword(s):  
Boundary Conditions ◽  
Natural Frequencies ◽  
Mixed Boundary ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Mixed Boundary Conditions ◽  
Integral Form ◽  
Mode Shapes ◽  
Different Boundary Conditions ◽  
Practical Applications

Vibration behavior of structures with parallelepiped shape—including beams, plates, and solids—are critical for a broad range of practical applications. In this paper we describe a new approach, referred to here as the three-dimensional spectral-Tchebychev (3D-ST) technique, for solution of three-dimensional vibrations of parallelepipeds with different boundary conditions. An integral form of the boundary-value problem is derived using the extended Hamilton’s principle. The unknown displacements are then expressed using a triple expansion of scaled Tchebychev polynomials, and analytical integration and differentiation operators are replaced by matrix operators. The boundary conditions are incorporated into the solution through basis recombination, allowing the use of the same set of Tchebychev functions as the basis functions for problems with different boundary conditions. As a result, the discretized equations of motion are obtained in terms of mass and stiffness matrices. To analyze the numerical convergence and precision of the 3D-ST solution, a number of case studies on beams, plates, and solids with different boundary conditions have been conducted. Overall, the calculated natural frequencies were shown to converge exponentially with the number of polynomials used in the Tchebychev expansion. Furthermore, the natural frequencies and mode shapes were in excellent agreement with those from a finite-element solution. It is concluded that the 3D-ST technique can be used for accurate and numerically efficient solution of three-dimensional parallelepiped vibrations under mixed boundary conditions.

Spread Spectrum Watermarking

2013 ◽  
pp. 559-588
Author(s):  
Santi P. Maity
Keyword(s):  
Real Time ◽  
Spread Spectrum ◽  
Hardware Implementation ◽  
High Reliability ◽  
Research Work ◽  
Hardware Architecture ◽  
Future Research ◽  
Hardware Realization ◽  
Field Programmable ◽  
Research Problems

Spread spectrum (SS) watermarking has proven to be efficient, robust and cryptographically secure. Each bit of watermark information is embedded over wide spectrum of the host signal based on spectrum spreading concept of SS modulation in digital communication and can easily be integrated with many existing data transmission scheme. This has made SS watermarking method more attractive during recent times for many non-conventional applications such as broadcast monitoring, security in communication, authentication and blind assessment of quality of services (QoS) for multimedia signals in mobile radio network. These applications essentially demand development of low cost algorithms so that they can be implemented on real time system through hardware realization. Hardware realization offers advantages over software realization in terms of less area, low execution time, low power, real-time performance, high reliability and also ease of integration with existing consumer electronics devices. This chapter first presents a brief review on hardware implementation of digital watermarking algorithms, followed by development of hardware architecture for spatial domain and fast Walsh transform (FWT) domain SS watermark system design using field programmable gate array (FPGA). A brief sketch on hardware implementation for biorthogonal wavelet based Hilbert transform is also shown that may be extended to design SS watermarking based on the concept of two previous architectures. Few challenges for hardware design of watermarking algorithms are then mentioned with an objective to give an idea how to develop watermarking algorithms so that it can be implemented on hardware. The chapter ends with few open research problems on hardware architecture as scope of future research work.

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