Numerical investigation for influence of pre-twist on stress behavioral characteristics of curved blade

Pavan Kishore Mamaduri,Chandra Sekhar Akula,Himam Saheb Shaik

doi:10.21595/vp.2018.20072

Abstract

To assist designers in developing blade design based on conventional and composite materials, an overview of material characteristics and stress analysis methods was taken for consideration. The significant effect of loading on the pre-twisted curved blade are evaluated in terms of its deflection and corresponding stresses. A more simplified approach was not satisfactory and furthermore to establish the feasibility of composite blade detailed stress analysis has been carried out for various pre-twist angles of composite and mild steel blade using a thick shell element. The suitability of the finite element method in predicting the stresses in externally loaded laminates is examined from the viewpoint of satisfaction of all boundary conditions and results. From the results it can be shown that the three-dimensional finite element analysis provides a useful insight for predicting deflection and stresses. The influence of ply angle for the distribution of inter laminar stresses along y and z-axis are determined.

Highlights

The application of pre-twisted blades in the recent decades have pulled a lot of consideration for marine propulsion, tilt rotors, wind turbine blades and helicopter applications
The manufacturing of the blade involves various parameters which are of complicated nature there by making the boundary conditions more complex which results in solving the structural analysis more cumber some process
Application of composite materials are more suitable than isotropic materials, which is mainly due to the high strength to weight ratio

Summary

Introduction

The application of pre-twisted blades in the recent decades have pulled a lot of consideration for marine propulsion, tilt rotors, wind turbine blades and helicopter applications. For a refined structural analysis of pre-twisted blades he suggested an appropriate treatment of section warping’s should be done From his perception, in the structural response of composite blades bending and torsion warping will play a significant role and should be taken directly into consideration. Mansfield [2] built up an adaptability formulation for thin walled composite beams made of two cell cylindrical tube section Most of these researchers have used FEM as a basic tool for carrying out the analysis. Taylor [3] used elementary beam theory for an aero foil cross section which are of asymmetric in nature and are pre-twisted along its length.

Methods

Results

Conclusion