Digital twin of the rotor-shaft of a lightweight electric motor during aerobatics loads

Abstract

Purpose

This paper aims to present airworthiness considerations regarding a shaft of an electric motor. A fatigue lifetime prediction analysis based on one-step load spectrum is performed during high-cycle fatigue. Time-dependent normal and shear stress components are estimated using a high-fidelity digital twin built in Siemens PLM Nx Nastran as a finite element model (FEM). Linear and centrifugal acceleration as well as gyroscopic moment, motor torque, propeller thrust and thermal loads are considered. The equivalent cyclic degree of utilisation and a safety margin against the slip of a press-fitted shaft to rotor hub connection is estimated.

Design/methodology/approach

A load analysis using FEM is presented. The numerically obtained results are verified on an analytical and a semi-empirical basis.

Findings

The shaft of the electric motor can sustain 74 h of operation if burdened with aerobatic loads. Its load capacity equals 48% for the overall safety factor of 2.25.

Practical implications

The paper presents a specific, easily identifiable advance in knowledge that can be applicable in safety flight analysis issues.

Originality/value

The work presents a rotor of a novel lightweight electric motor for aircraft applications, which is a successor of the electric motor set recently in Extra 330E. The work delivers a computational estimation of the shaft life.

Citation

Goraj, R. (2020), "Digital twin of the rotor-shaft of a lightweight electric motor during aerobatics loads", Aircraft Engineering and Aerospace Technology, Vol. 92 No. 9, pp. 1319-1326. https://doi.org/10.1108/AEAT-11-2019-0231