scholarly journals Bending and vibration of a discontinuous beam with a curvic coupling under different axial forces

2020 ◽  
Vol 15 (3) ◽  
pp. 417-429
Author(s):  
Heng Liu ◽  
Jie Hong ◽  
Dayi Zhang
Keyword(s):  
Normal Function ◽  
Vibration Characteristics ◽  
Vibration Frequencies ◽  
Spring Stiffness ◽  
Axial Loads ◽  
Deflection Curve ◽  
Axial Forces ◽  
Continuous Beams ◽  
Proposed Model ◽  
Undetermined Coefficient

Abstract The transverse stiffness and vibration characteristics of discontinuous beams can significantly differ from those of continuous beams given that an abrupt change in stiffness may occur at the interface of the former. In this study, the equations for the deflection curve and vibration frequencies of a simply supported discontinuous beam under axial loads are derived analytically on the basis of boundary, continuity, and deformation compatibility conditions by using equivalent spring models. The equation for the deflection curve is solved using undetermined coefficient methods. The normal function of the transverse vibration equation is obtained by separating variables. The differential equations for the beam that consider moments of inertia, shearing effects, and gyroscopic moments are investigated using the transfer matrix method. The deflection and vibration frequencies of the discontinuous beam are studied under different axial loads and connection spring stiffness. Results show that deflection decreases and vibration frequencies increase exponentially with increasing connection spring stiffness. Moreover, both variables remain steady when connection spring stiffness reaches a considerable value. Lastly, an experimental study is conducted to investigate the vibration characteristics of a discontinuous beam with a curvic coupling, and the results exhibit a good match with the proposed model.

iTSP-PseAAC: Identify Tumor Suppressor Proteins by Using Fully Connected Neural Network and PseAAC

2021 ◽  
Vol 15 ◽  
Author(s):  
Muhammad Awais ◽  
Waqar Hussain ◽  
Nouman Rasool ◽  
Yaser Daanial Khan
Keyword(s):  
Tumor Suppressor ◽  
Cross Validation ◽  
Control Cell ◽  
Normal Function ◽  
In Vivo Studies ◽  
Tumor Suppressor Proteins ◽  
Proposed Model ◽  
Self Consistency

Background: The uncontrolled growth due to accumulation of genetic and epigenetic changes as a result of loss or reduction in the normal function of Tumor Suppressor Genes (TSGs) and Pro-oncogenes is known as cancer. TSGs control cell division and growth by repairing of DNA mistakes during replication and restrict the unwanted proliferation of a cell or activities, those are the part of tumor production. Objectives: This study aims to propose a novel, accurate, user-friendly model to predict tumor suppressor proteins, which would be freely available to experimental molecular biologists to assist them using in vitro and in vivo studies. Methods: The predictor model has used the input feature vector (IFV) calculated from the physicochemical properties of proteins based on FCNN to compute the accuracy, sensitivity, specificity, and MCC. The proposed model was validated against different exhaustive validation techniques i.e. self-consistency and cross-validation. Results: Using self-consistency, the accuracy is 99%, for cross-validation and independent testing has 99.80% and 100% accuracy respectively. The overall accuracy of the proposed model is 99%, sensitivity value 98% and specificity 99% and F1-score was 0.99. Conclusion: It concludes, the proposed model for prediction of the tumor suppressor proteins can predict the tumor suppressor proteins efficiently, but it still has space for improvements in computational ways as the protein sequences may rapidly increase, day by day.

Self-Vibration Characteristics of Plane Gate in Inverted Siphon Project

2012 ◽  
Vol 160 ◽  
pp. 64-68
Author(s):  
Hui Fang Xue ◽  
You Wang
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Element Model ◽  
Vibration Characteristics ◽  
The Self ◽  
Vibration Modes ◽  
Vibration Frequencies ◽  
Small Opening ◽  
First Order ◽  
Inverted Siphon

Based on the vibration problem of the plane gate in the inverted siphon exit of a large-scale hydraulic project in northern Xinjiang, the software ANSYS is used to build the entity model and finite element model. Considering the influence of fluid-solid coupling, the self-vibration characteristics of the gate in the water and without water are analyzed. The first six self-vibration frequencies and vibration modes of the gate are calculated. The results show that the height of water has a significant impact on the self-vibration frequencies of the plane gate. The first order natural frequency on the condition of small opening is decreased by 28.5%. It shows that the structure of the plane gate must be improved.

Axial distortion of airways in the lung

1983 ◽  
Vol 54 (1) ◽  
pp. 185-190 ◽  
Author(s):  
M. J. Kallok ◽  
S. J. Lai-Fook ◽  
M. A. Hajji ◽  
T. A. Wilson
Keyword(s):  
Elastic Tube ◽  
Shear Stresses ◽  
Coupling Mechanism ◽  
Airway Wall ◽  
Axial Loads ◽  
Elastic Continuum ◽  
Airway Lumen ◽  
Axial Forces ◽  
Mathematical Analyses ◽  
The Continuum

Axial loads were applied around the circumference of an airway lumen by pulling on a cup-shaped anchor that embedded itself in the airway wall. Axial displacements were measured as a function of distance from the load, and the data were compared to the results of mathematical analyses of continuum mechanics models. In the modeling it was assumed that the elastic tube representing the airway is bonded to the surrounding elastic continuum representing the parenchyma and that axial forces are transmitted between the tube and the continuum by shear stresses at the interface. The agreement between the measured and computed axial displacements supports the hypothesis that the shear stresses are the dominant coupling mechanism. The following quantitative relations between force and displacement were obtained. The axial displacement produced by the load L was approximately 0.05 L/pi alpha mu, where alpha is the airway radius and mu is the shear modulus of the parenchyma. The displacement decayed to approximately one-half this maximal value at two diameters from the load.

DYNAMIC PERFORMANCE OF POST-BUCKLED PRECOMPRESSED PIEZOELECTRIC ACTUATOR ELEMENTS

2012 ◽  
Vol 12 (05) ◽  
pp. 1250042 ◽  
Author(s):  
GEORGIOS GIANNOPOULOS ◽  
MARK GROEN ◽  
ROELOF VOS ◽  
RON BARRETT
Keyword(s):  
Finite Element ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Past Research ◽  
Element Model ◽  
Axial Loads ◽  
New Class ◽  
Axial Forces ◽  
Bimorph Actuators ◽  
Full Force

Post-buckled precompressed (PBP) piezoelectric elements have recently been used to enable a new class of actuators that are able to provide far higher deflections compared to the traditional bimorph piezoelectric actuators while maintaining full force and moment generating capabilities. Past research has proven that PBP actuators are capable of generating deflections three times higher than conventional bimorph actuators. In this paper, this work has been extended to the dynamic response realm and the performance of PBP actuators is investigated under various axial loads, at various actuation frequencies. Both analytical and finite element models have been developed in order to evaluate the performance of the actuator regarding the natural frequency shift under increased axial loads. Experimental verification has shown that the overall damping ratio of the structure is a function of the axial forces. Values derived from experiments have been used in the Finite Element model to predict the displacement output, phase angle shifting and end rotation. Numerical and analytical results correlate very well with the experiments and thus give credit to the formulation presented in this work.

scholarly journals Measurements of Forces and Selected Surface Layer Properties of AW-7075 Aluminum Alloy Used in the Aviation Industry after Abrasive Machining

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3707 ◽  
Author(s):  
Matuszak ◽  
Kłonica ◽  
Zagórski
Keyword(s):  
Surface Layer ◽  
Experimental Studies ◽  
Free Surface Energy ◽  
Aviation Industry ◽  
Spring Stiffness ◽  
Abrasive Machining ◽  
Thin Walled Structures ◽  
Axial Forces ◽  
Strongly Connected ◽  
Thin Walled

Measurements of forces during machining, especially thin-walled structures typical of the aviation industry, are important in the aspect of instability caused by vibration. One of the last stages of manufacturing by machining is the finishing treatment and deburring of the product’s edges. Brushes with ceramic fibres are often employed in deburring, especially for large-sized elements specific to the aviation industry due to the possibility of automatic machining directly on machining centres. This study set out to analyse the effect of variable brushing conditions on axial forces and the selected surface layer properties of AW-7075 aluminium alloy. Experimental studies have examined factors such as surface roughness and topography, axial cutting force in ceramic brush treatment and surface free energy in the aspect of adhesive joints. The tested variable process parameters were the fibre material and the adjustment sleeve spring stiffness. Based on the tests, it was found that the axial force applied by the brush was more strongly connected with the spring stiffness rather than the type of bristle. For most cases, an increase in the value of free surface energy after brushing was observed compared to the initial machining which was milling.

Vibration characteristics and thermoelastic analysis of the supersonic composite laminated panel with arbitrary elastic boundaries

2018 ◽  
Vol 233 (7) ◽  
pp. 2503-2517 ◽  
Author(s):  
Huagang Lin ◽  
Dengqing Cao ◽  
Yuqian Xu
Keyword(s):  
Ritz Method ◽  
Vibration Characteristics ◽  
Spring Stiffness ◽  
Aerodynamic Stability ◽  
Coupled Mode ◽  
Elastic Boundary ◽  
Laminated Panels ◽  
The Stability ◽  
New Phenomena ◽  
Admissible Functions

The novelty of this study is to present a theoretical approach to investigate the dynamic behaviors of the laminated panels under arbitrary elastic boundary conditions. The motion equations of panels considering the first order piston theory are derived using Hamilton principle. A solution of computing the vibration characteristics of a panel with arbitrary elastic boundaries is proposed based on the Rayleigh–Ritz method, in which the admissible functions are constructed by a set of characteristic orthogonal polynomials employing the Gram–Schmidt process; the support boundary is modeled by introducing the technology of artificial springs. The effects of spring stiffness and different boundaries on the dynamic characteristics and thermal aeroelastic behaviors are presented in detail. Numerical results show that the small ply angle and large spring stiffness are helpful to improve the aerodynamic stability. Multiple new phenomena have been observed, e.g. the phenomena of mode jumping and the alterations of coupled mode orders. Moreover, the thermal loads and aerodynamic loads play an opposite effect on the stability of composite panels.

EXACT VIBRATION FREQUENCIES AND MODES OF BEAMS WITH INTERNAL RELEASES

2002 ◽  
Vol 02 (01) ◽  
pp. 63-75 ◽  
Author(s):  
M. EISENBERGER
Keyword(s):  
Stiffness Matrix ◽  
Natural Frequencies ◽  
Dynamic Stiffness ◽  
Beam Element ◽  
Mode Shapes ◽  
Vibration Frequencies ◽  
Dynamic Stiffness Matrix ◽  
Continuous Beams ◽  
Stiffness Method ◽  
Dynamic Stiffness Method

The exact vibration frequencies of continuous beams with internal releases are found using the dynamic stiffness method. Two types of releases are considered: hinge and sliding discontinuities. First, the exact dynamic stiffness matrix for a beam element with a release is derived and then used in the assembly of the structure dynamic stiffness matrix. The natural frequencies are found as the values of frequency that make this matrix singular. Then the mode shapes are found exactly. Examples are given for continuous beams with different releases.

INFLUENCE OF THE INPLANE BOUNDARY CONDITIONS ON THE VIBRATION FREQUENCIES AND BUCKLING LOAD OF RIBBED PLATES

2002 ◽  
Vol 02 (01) ◽  
pp. 25-43 ◽  
Author(s):  
EVANGELOS J. SAPOUNTZAKIS ◽  
JOHN T. KATSIKADELIS
Keyword(s):  
Boundary Conditions ◽  
Mass Matrix ◽  
Buckling Load ◽  
Vibration Frequencies ◽  
Lumped Mass ◽  
Analog Equation Method ◽  
Axial Forces ◽  
Adopted Model ◽  
Dynamic Criterion ◽  
Analog Equation

In this paper, the influence of the inplane boundary conditions on the vibration frequencies and the buckling load of plates reinforced with a system of parallel beams is presented. The adopted model for the dynamic analysis of the ribbed plate takes into account the resulting inplane forces and deformations of the plate as well as the axial forces and deformations of the beam, due to combined response of the system. The analysis consists in isolating the beams from the plate by sections parallel to the lower outer surface of the plate. The analysis of the vibration problem of a ribbed plate subjected to inplane forces is based on the capability to establish a flexibility matrix with respect to a set of nodal mass points using the Analog Equation Method (AEM) for the static ribbed plate problem. Moreover, a lumped mass matrix is constructed from the tributary mass areas to the nodal mass points. The buckling load is established using the dynamic criterion. From the obtained results it is shown that both the vibration frequencies and the buckling load may be significantly influenced by the inplane boundary conditions.

Vibration and Frequency Analysis of Non-Uniform Timoshenko Beams Subjected to Axial Forces

2003 ◽  
Author(s):  
A. R. Ohadi ◽  
H. Mehdigholi ◽  
E. Esmailzadeh
Keyword(s):  
Stability Analysis ◽  
Boundary Conditions ◽  
Axial Force ◽  
Frequency Equation ◽  
Axial Loads ◽  
Various Boundary Conditions ◽  
Axial Forces ◽  
First Case ◽  
The Stability ◽  
Elastically Supported

Dynamic and stability analysis of non-uniform Timoshenko beam under axial loads is carried out. In the first case of study, the axial force is assumed to be perpendicular to the shear force, while for the second case the axial force is tangent to the axis of the beam column. For each case, a pair of differential equations coupled in terms of the flexural displacement and the angle of rotation due to bending was obtained. The parameters of the frequency equation were determined for various boundary conditions. Several illustrative examples of uniform and non-uniform beams with different boundary conditions such as clamped supported, elastically supported, and free end mass have been presented. The stability analysis, for the variation of the natural frequencies of the uniform and non-uniform beams with the axial force, has also been investigated.

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