Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Journal of Theoretical and Applied Mechanics

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Prediction of acoustic modal characteristics of two dimensional irregular shaped cavities by impedance mobility compact matrix (IMCM) approach

Reddy Veerabhadra, Venkatesham B., Narayana Murthy Vijaya

Journal of Theoretical and Applied Mechanics

2021

Vol. 59 nr 1

95--107

In this paper, the impedance and mobility compact matrix (IMCM) method for prediction of acoustic modal characteristics of two dimensional irregular cavities with the rigid wall boundary is presented. This method consists of discretizing the whole cavity into a series of subcavities either of regular or irregular shape. Continuity of both pressure and veloc- ity between adjacent subcavities is ensured using a virtual membrane with zero mass and stiffness. Mathematical formulation for acoustic cavities with the irregular shape has been explained in detail. A finite element model has been developed to calculate the acoustic natural frequency and mode shape. The proposed method is validated using a regular and irregular cavity and compared with finite element modelling results and available results in the literature.

Free vibrational analysis of rectangular ducts with different joint conditions

Jade N., Venkatesham B.

Journal of Theoretical and Applied Mechanics

2018

Vol. 56 nr 4

1069--1081

Rectangular ducts are fabricated using thin sheets of a metal with different joint conditions. Due to the presence of these joints, ducts deviate from their assumptive ideal shapes. The objective of the present work is to study the effect of different joint conditions and wall thickness on dynamic characteristics of the ducts. Experimental Modal Analysis (EMA) is performed on three rectangular ducts of different joint types. Numerical Modal Analysis (NMA) is also performed by considering that the ducts are of ideal rectangular shape (without joint condition). Correlation analysis is performed between EMA and NMA in terms of Modal Assurance Criteria (MAC), Relative Frequency Difference (RFD) plots and auto-MAC. It is observed that natural frequencies are in good agreement but there is a discrepancy in mode shapes.