Buckling Analysis of Hollow Microneedle in Transdermal Drug Delivery

2016 ◽  
Author(s):  
N. Raja Rajeswari ◽  
P. Malliga ◽  
B. K. Gnanavel
Keyword(s):  
Drug Delivery ◽  
Transdermal Drug Delivery ◽  
Reaction Force ◽  
Vital Role ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Insertion Force ◽  
Element Analysis ◽  
Critical Buckling Load ◽  
Hollow Microneedle

In biomedical field, the microneedles have gained popularity in the transdermal drug delivery applications. A hollow out-of-plane microneedle with bevel shaped tip, made up of silicon material is considered in this paper. The safe insertion of such microneedles into the soft tissue without breakage plays a vital role in the design of microneedles. The primary mode of failure often found in microneedles is buckling. When the microneedle is applied with an insertion force (F) larger than the critical buckling load (Pcr), it may suffer from buckling. In this paper, the buckling analysis of silicon microneedle is performed using Finite Element Analysis. The equilibrium equation of Love’s (1944) thin rod theory is used to study the buckling effect of microneedle. A non-linear Eigen value buckling analysis of the hollow microneedle is performed. The fundamental mode 1 and the critical mode 813 are discussed. The deflection, stresses and reaction force are analysed for both the modes. The critical buckling load (Pcr) is determined to be 0.39 N and if the microneedle is applied with insertion force within this value of critical buckling load, it avoids buckling. Therefore, this critical buckling load is taken as a conservative result for designing the microneedle.

scholarly journals Buckling analysis of Functionally Graded Natural Fiber-Flyash-Epoxy (FGNFFE) Cylinder

2019 ◽  
Vol 8 (6) ◽  
pp. 4260-4265
Keyword(s):  
Hollow Cylinder ◽  
Natural Fiber ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Buckling Load ◽  
Common Element ◽  
Element Analysis ◽  
Modern Material ◽  
Critical Buckling Load ◽  
Structural Applications

A hollow cylinder or a pipe is a common element used in structural applications. Now days in the era of new material development, replacement of consventional materials by modern material are of primary choice for the researchers and developers as well. This paper presents the bucking analysis of functionally graded natural-fiber-flyash-epoxy (FGNFFE) hollow cylinders using FEA. In the first part, a mathematical model for buckling analysis is developed to get the dynamic behavior of hollow cylinder under free vibration. Initial five modes of buckling analysis are performed by theoretical, finite element analysis and experimentation. Accordingly Mechanical properties are obtained and used for buckling study in FEA environment as being a cylindrical structure to the design, it is subjected to compression and buckling due to self weight and due to external load is very common. The critical buckling load is determined by FEA study and compared with the experimental value. Further the study extended by optimizing the critical buckling load and stress with respect to the ingredients and other designed parameters and discussed.

scholarly journals A Novel 3D Printed Hollow Microneedle Microelectromechanical System for Controlled, Personalised Transdermal Drug Delivery

2020 ◽  
pp. 101815
Author(s):  
Sophia N. Economidou ◽  
Md. Jasim Uddin ◽  
Manuel J. Marques ◽  
Dennis Douroumis ◽  
Wan Ting Sow ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Transdermal Drug Delivery ◽  
Microelectromechanical System ◽  
Hollow Microneedle ◽  
3D Printed

Thermal buckling analysis of double-walled carbon nanotubes considering the small-scale length effect

2011 ◽  
Vol 225 (1) ◽  
pp. 248-256 ◽  
Author(s):  
A Ghorbanpour Arani ◽  
M Mohammadimehr ◽  
A R Saidi ◽  
S Shogaei ◽  
A Arefmanesh
Keyword(s):  
Temperature Change ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Small Scale ◽  
Buckling Mode ◽  
Critical Buckling Load ◽  
Winkler Model ◽  
Non Local ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this article, the buckling analysis of a double-walled carbon nanotube (DWCNT) subjected to a uniform internal pressure in a thermal field is investigated. The effects of the temperature change, the surrounding elastic medium based on the Winkler model, and the van der Waals forces between the inner and the outer tubes are considered using the continuum cylindrical shell model. The small-length scale effect is also included in the present formulation. The results show that there is a unique buckling mode corresponding to each critical buckling load. Moreover, it is shown that the non-local critical buckling load is lower than the local critical buckling load. It is concluded that, at low temperatures, the critical buckling load for the infinitesimal buckling of a DWCNT increases as the magnitude of temperature change increases whereas at high temperatures, the critical buckling load decreases with the increasing of the temperature.

Buckling analysis of functionally graded annular sector plates resting on elastic foundations

2010 ◽  
Vol 225 (2) ◽  
pp. 312-325 ◽  
Author(s):  
A Naderi ◽  
A R Saidi
Keyword(s):  
Boundary Conditions ◽  
Elastic Foundation ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Elastic Foundations ◽  
Annular Sector ◽  
Sector Plate ◽  
Annular Sector Plate

In this study, an analytical solution for the buckling of a functionally graded annular sector plate resting on an elastic foundation is presented. The buckling analysis of the functionally graded annular sector plate is investigated for two typical, Winkler and Pasternak, elastic foundations. The equilibrium and stability equations are derived according to the Kirchhoff's plate theory using the energy method. In order to decouple the highly coupled stability equations, two new functions are introduced. The decoupled equations are solved analytically for a plate having simply supported boundary conditions on two radial edges. Satisfying the boundary conditions on the circular edges of the plate yields an eigenvalue problem for finding the critical buckling load. Extensive results pertaining to critical buckling load are presented and the effects of boundary conditions, volume fraction, annularity, plate thickness, and elastic foundation are studied.

Buckling Analysis of Shells with a Circumferential Crack

2006 ◽  
Vol 306-308 ◽  
pp. 55-60
Author(s):  
I.S. Putra ◽  
T. Dirgantara ◽  
Firmansyah ◽  
M. Mora
Keyword(s):  
Boundary Conditions ◽  
Cylindrical Shells ◽  
Buckling Analysis ◽  
Numerical Results ◽  
Buckling Load ◽  
Numerical Analyses ◽  
Radius Of Curvature ◽  
Critical Buckling Load ◽  
Different Boundary Conditions ◽  
Circumferential Crack

In this paper, buckling analysis of cylindrical shells with a circumferential crack is presented. The analyses were performed both numerically using FEM and experimentally. The numerical analyses and experiments were conducted for several crack lengths and radius of curvature, and two different boundary conditions were applied, i.e. simply support and clamp in all sides. The results show the effect of the presence of crack to the critical buckling load of the shells. There are good agreements between experimental and numerical results.

Buckling Analysis of the Hydraulic Support Column Based on ANSYS

2012 ◽  
Vol 500 ◽  
pp. 434-439
Author(s):  
Y.K. Zhang ◽  
L.J. Xiao ◽  
Rui Chuan Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Result ◽  
Theoretical Calculation ◽  
Buckling Analysis ◽  
Hydraulic Support ◽  
Element Analysis ◽  
Critical Buckling Load ◽  
Analogue Simulation ◽  
The Finite Element Analysis

The buckling of hydraulic support column is analyzed theoretically with the theory of the pressure rod stability. 3D digital model of the hydraulic support column is built with Pro/E, also buckling analysis and analogue simulation with ANSYS to the model are carried out. The critical buckling load of the column is obtained. The buckling analysis result is picked up and discussed, and compared with the theoretical calculation. The finite element analysis result is agreed with the theoretical result.

scholarly journals Mechanical Buckling Analysis of Saturated Porous Functionally Graded Elliptical Plates Subjected to In-Plane Force Resting on Two Parameters Elastic Foundation Based on HSDT

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Mohammad Hossein Sharifan ◽  
Mohsen Jabbari
Keyword(s):  
Elastic Foundation ◽  
Ritz Method ◽  
Shear Deformation Theory ◽  
Potential Energy Function ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Mechanical Buckling ◽  
Two Parameters

Abstract In this paper, mechanical buckling analysis of a functionally graded (FG) elliptical plate, which is made up of saturated porous materials and is resting on two parameters elastic foundation, is investigated. The plate is subjected to in-plane force and mechanical properties of the plate assumed to be varied through the thickness of it according to three different functions, which are called porosity distributions. Since it is assumed that the plate to be thick, the higher order shear deformation theory (HSDT) is employed to analyze the plate. Using the total potential energy function and using the Ritz method, the critical buckling load of the plate is obtained and the results are verified with the simpler states in the literature. The effect of different parameters, such as different models of porosity distribution, porosity variations, pores compressibility variations, boundary conditions, and aspect ratio of the plate, is considered and has been discussed in details. It is seen that increasing the porosity coefficient decreases the stiffness of the plate and consequently the critical buckling load will be reduced. Also, by increasing the pores' compressibility, the critical buckling load will be increased. Adding the elastic foundation to the structure will increase the critical buckling load. The results of this study can be used to design more efficient structures in the future.

Nonlinear Mechanics of Interlocking Cantilevers

2017 ◽  
Vol 84 (12) ◽  
Author(s):  
Joseph J. Brown ◽  
Ryan C. Mettler ◽  
Omkar D. Supekar ◽  
Victor M. Bright
Keyword(s):  
Large Deflection ◽  
Elliptic Integral ◽  
Contact Point ◽  
Reaction Force ◽  
Insertion Force ◽  
Element Analysis ◽  
Fast Analysis ◽  
Analysis And Design ◽  
Physical Measurements ◽  
Compliant Systems

The use of large-deflection springs, tabs, and other compliant systems to provide integral attachment, joining, and retention is well established and may be found throughout nature and the designed world. Such systems present a challenge for mechanical analysis due to the interaction of contact mechanics with large-deflection analysis. Interlocking structures experience a variable reaction force that depends on the cantilever angle at the contact point. This paper develops the mathematical analysis of interlocking cantilevers and provides verification with finite element analysis and physical measurements. Motivated by new opportunities for nanoscale compliant systems based on ultrathin films and two-dimensional (2D) materials, we created a nondimensional analysis of retention tab systems. This analysis uses iterative and elliptic integral solutions to the moment–curvature elastica of a suspended cantilever and can be scaled to large-deflection cantilevers of any size for which continuum mechanics applies. We find that when a compliant structure is bent backward during loading, overlap increases with load, until a force maximum is reached. In a force-limited scenario, surpassing this maximum would result in snap-through motion. By using angled cantilever restraint systems, the magnitude of insertion force relative to retention force can vary by 50× or more. The mathematical theory developed in this paper provides a basis for fast analysis and design of compliant retention systems, and expands the application of elliptic integrals for nonlinear problems.

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