# Technical Papers and Presentations

Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

### Lamb Waves in Fluid-Loaded Plates

T. Kaufmann[1], F. Kassubek[1], D. Pape [1], M. Lenner[1]

Lamb waves are elastic waves propagating in free solid plates. In the case of plates loaded with a fluid, the equations describing these waves have to be modified to include the effects of the fluid. In our work we have tackled this problem using COMSOL Multiphysics®. We have used the two-dimensional plane strain model of the solid mechanics interface to calculate the eigenmodes of the coupled ...

### Piezotyres

T. Madhuranath[1], R. Praharsha[1], K. Srinivasa Rao[1]
[1]Lakireddy Bali Reddy College of Engineering, Mylavaram, Andhra Pradesh, India

Access to electricity has become a major problem. In the process of solving this problem we should consider even a small source of electricity. Piezotyres are made to produce electricity from vehicle tyres. For this we have used a piezoelectric property, one of the natural wonder. COMSOL Multiphysics® was used to design and simulate it virtually. We have used different materials in the software ...

### Energy Transformation Damping

G.S. Mulder[1]
[1]Leiden, The Netherlands

A model for material damping is presented in terms of internal friction and in terms of a variation of stiffness. In the latter case the idea is that the stiffness increases if elastic energy is stored and decreases if elastic energy is released. In case of a single mass spring system “stiffness” refers to the stiffness of the spring; in case of a continues object &ldquo ...

### Dynamics of Slender Structures

K. Lund
Kurt Lund Consulting, Del Mar, CA , USA

The present work formulates the dynamics of a slender structure as a long beam. This results in a PDE that is fourth-order in space, and second order in time. In COMSOL the coupling method is used to decompose this problem into two second-order equations, one for displacements, and one for bending moments, which are then solved to obtain frequencies and mode shapes. For verification of ...

### Optimal Placement of Piezoelectric Plates to Control Multimode Vibrations of Rotating Beam

F. Botta[1], D. Dini[2], S. Gentili[1], G. Cerri[1]
[1]Dipartimento di Ingegneria Meccanica e Industriale, Università degli Studi di Roma Tre, Roma, Italy
[2]Department of Mechanical Engineering, Imperial College London, London, United Kingdom

Turbomachines blades are forced by a load resulting from the interaction with the fluid. The consequent vibrations, and the associated fatigue phenomena, can give catastrophic failures and the reduction of the blades life. It could be increased if damping system are used. The piezoelectric materials has received considerable attention by many researcher for their potential application in the ...

### Thermal Stress in a Zero Thermal Expansion Composite

C. Romao, and M. White
Dept. of Chemistry and Institute for Research in Materials
Dalhousie University
Halifax, NS

A series of 2-D finite element models of a ZrO2-ZrW2O8 composite system were created in COMSOL Multiphysics to study the effect of pores between the matrix (ZrO2) and filler (ZrW2O8) materials. Pores were modeled as ellipses concentric with the filler particles. Seventeen model geometries of varying microstructure were studied in order to determine correlations between microstructural ...

### Micro Mechanical Exploration of Composites for Superior Properties

R. C. Thiagarajan, and K. V. Chiranjeevi
ATOA Scientific Technologies Private Limited
Bangalore, India

The predictive engineering of materials is matured from predicting properties from known morphology or constituents to engineering novel morphology for superior properties. The focus of this paper is about implementation of computational material mechanics modeling method in COMSOL Multiphysics software for engineering the constituents for superior properties. A brief review of property ...

### Numerical and Experimental Analysis of Natural and Mixed Convection Heat Transfer for Vertically Arranged DIMM

G. Petrone, and G. Cammarata
University of Catania, Catania, Italy

It is commonly recognized that careful thermal design of electronic equipments represents an unavoidable pre-production step in order to ensure reliability and performance of those components during their functioning. This paper mainly concerns a comparison between experimental and numerical results obtained in studying thermal dissipation in natural and mixed convection conditions for RAM ...

### Numerical Modelling Of Moisture Related Mechanical Stress In Wooden Cylindrical Objects Using COMSOL: A Comparative Benchmark

H. Schellen, and J. Van Schijndel
Eindhoven University of Technology, Eindhoven, The Netherlands

For preservation of artefacts in a museum the indoor climate is often restricted to a very narrow interval for temperature, but most of all for relative humidity. In old buildings the museum conditions of artefacts, e.g. near cold walls, mostly are not in line with museum recommendations.To have an impression of indoor museum climates in old buildings, a large number of case studies were carried ...

### Novel Simulation of a Voltage-Driven Electro-Thermo-Mechanical MEMS Self-Oscillator

S. Ouenzerfi [1,2,3], H.A.C. Tilmans [2], S. El-Borgi[3,4], X. Rottenberg [2]
[1] KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh, KSA
[2] IMEC, Leuven, Belgium
[3] Applied Mechanics and Systems Research Laboratory, Tunisia Polytechnic School, University of Carthage, La Marsa, Tunesia
[4] Texas A&M University at Qatar, Mechanical Engineering Program, Engineering Building, Doha, Qatar

This paper presents the modeling and simulation of electro-thermo-mechanical self-oscillators, an emerging type of M/NEMS-enabled timing devices in which sustaining electronic amplifiers are not required for their operation. Indeed, they realize amplification in the mechanical domain and feedback by crossing three physical domains: electrical, thermal and mechanical. In a previous work [1], we ...