Verification and application of bird strike analysis for the design of high-speed helicopter composite cowlings

Bird strikes are an important phenomenon that must be taken into consideration when designing aircraft. A bird impact experiment provides a direct method to examine the bird strike resistance. However, the design of the aircraft structures usually involves many iterations of design-manufacturing-test and conducting bird impact experiments is not only time consuming but also costly. The aim of this work is to show the application of test verified numerical simulation for the design of composite cowlings of the high-speed helicopter.

Download Full-text

A direct method-based strength evaluation of the cast aluminum beam used in a high-speed train

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409719825515 ◽

2019 ◽

Vol 233 (9) ◽

pp. 896-905

Author(s):

Songhua Huang ◽

Yugong Xu ◽

Alexander Bezold ◽

Lele Zhang ◽

Geng Chen ◽

...

Keyword(s):

High Speed ◽

Direct Method ◽

Weight Ratio ◽

Rolling Stock ◽

High Speed Train ◽

Cast Aluminum ◽

Aluminum Casting ◽

Beam Structure ◽

Aluminum Beam ◽

A Direct Method

In this paper, the authors elaborate how numerical techniques developed from the direct method can be used to predict the load-bearing capacity of the aluminum casting beam structure which is presently used in the Chinese high-speed train CRH5A. The numerical method introduced in this paper is formulated based on the Melan's static theorem; thus, it determines the strength of the cast aluminum beam under both monotonic and cyclic loads without following the entire load profile. In addition to constructing the plastic and shakedown limits of the component, the proposed approach is also employed to study how stiffeners' thickness on the key areas influences the feasible load domains. Based on the intensive sensitivity analysis, an optimal thickness has been determined which gives the highest strength-to-weight ratio. To this end, the paper confirms that the direct method is a viable means for designing structures used in the rolling stock.

Download Full-text

TRAJECTORY BASED 3D FRAGMENT TRACKING IN HYPERVELOCITY IMPACT EXPERIMENTS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-1175-2018 ◽

2018 ◽

Vol XLII-2 ◽

pp. 1175-1181 ◽

Cited By ~ 1

Author(s):

E. Watson ◽

H.-G. Maas ◽

F. Schäfer ◽

S. Hiermaier

Keyword(s):

Measurement Technique ◽

Experimental Measurement ◽

High Speed ◽

Space Debris ◽

Hypervelocity Impact ◽

Experimental Setup ◽

Velocity Data ◽

Hypervelocity Impacts ◽

Impact Experiment ◽

Impact Experiments

Collisions between space debris and satellites in Earth’s orbits are not only catastrophic to the satellite, but also create thousands of new fragments, exacerbating the space debris problem. One challenge in understanding the space debris environment is the lack of data on fragmentation and breakup caused by hypervelocity impacts. In this paper, we present an experimental measurement technique capable of recording 3D position and velocity data of fragments produced by hypervelocity impact experiments in the lab. The experimental setup uses stereo high-speed cameras to record debris fragments generated by a hypervelocity impact. Fragments are identified and tracked by searching along trajectory lines and outliers are filtered in 4D space (3D&thinsp;+&thinsp;time) with RANSAC. The method is demonstrated on a hypervelocity impact experiment at 3.2&thinsp;km/s and fragment velocities and positions are measured. The results demonstrate that the method is very robust in its ability to identify and track fragments from the low resolution and noisy images typical of high-speed recording.

Download Full-text