Dynamic Response Analysis of Composite Tether Structure to Airborne Wind Energy System under Impulsive Load

Kwangtae Ha

doi:10.3390/app11010166

Abstract

The tether structure plays the role of transferring the traction force of an airborne wind energy system (AWES) to the fixed or mobile ground system with less motion and maintains the flying airborne system as a critical component. The implementation of a geometrically tailored tether design in an AWES could avoid unwanted snap-through failure, which can be take place in a conventional tether structure under impulsive loading. This concept relies on the redundant load path of the composite structure composed of tailored length and strength. In this study, the dynamic response of this composite tether structure to airborne wind energy systems, such as a kite wind power system, was analytically investigated. Also, for very long tether applications, an approximate model of the tether response was developed, which resulted in a dramatic reduction of computational efforts while preserving the accuracy quite well compared to the exact solution.

Highlights

3 alsothe shows the traditional tetherThe structure made a single element constant cross-sectional areas the longitudinal bothoftraditional andwith tailored tether structures arealong shown in Figure 3direcas straight tion with the same total length
When the distance between the two masses is less than the total tether length, the effect of the external load on the structure is negligible
Otherwise—that is, when the distance between the two mass systems is greater than the tether length—the tether structure is subjected to impul4 of 12 sive loading

Summary

Introduction

The structural member comprised the system incalled the longitudinal direction, the in main elements and connectors w ato primary load path, the primary element, connected parallel to a longer secondary jected tocalled the tension loads.element, If all the elements the same geometric and load path, the secondary at amain pair of common had nodes Both primary and secondary elements were combined to form the connector element, which had the sum of distributions, the failure probabilities of the main elements were the same. 3 alsothe shows the traditional tetherThe structure made a single element constant cross-sectional areas the longitudinal bothoftraditional andwith tailored tether structures arealong shown in Figure 3direcas straight tion with the same total length.

Application of a Tailored Tether to AWES

Simplification of an AWES with a Tailored Structure

Dynamic

Numerical Results

Conclusions