INCAS BULLETIN, Volume 9, Issue 1/ 2017, pp. 77 – 83 ISSN 2066 – 8201 VTVL concept optimisation of the landing gear Camelia Elena MUNTEANU* ,1 , Alexandru-Mihai CISMILIANU 1 , Daniela BARAN 1 *Corresponding author 1 INCAS – National Institute for Aerospace Research “Elie Carafoli”, Bd. Iuliu Maniu 220, Bucharest 061126, Romania, munteanu.camelia@incas.ro*, cismilianu.alexandru@incas.ro, baran.daniela@incas.ro DOI: 10.13111/2066-8201.2017.9.1.8 Received: 27 January 2017/ Accepted: 23 February 2017/ Published: March 2017 © Copyright 2017, INCAS. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) International Conference of Aerospace Sciences “AEROSPATIAL 2016” 26 - 27 October 2016, Bucharest, Romania, (held at INCAS, B-dul Iuliu Maniu 220, sector 6) Section 4 – Materials and Structures Abstract: Vertical takeoff, vertical landing (VTVL) is a subject of international interest at the moment thanks to the successful recovery of the Blue Origin vehicle. Aggressive weight targets with a short development time in the aerospace and space industry clearly need an integration of advanced computer aided structural optimization methods. Topological optimization is used from the concept phase of a design process development in order to obtain a fundamental design approach. The aim of the article is to determine the principal directions for distribution of the material for a VTVL landing gear within the specified volume in order to obtain the initial design approach. To achieve the maximum performance within the studied component, the result is then refined from a manufacturability point of view. The use of such methods notably reduces the development iterations between the design and stress departments. Thus, the overall time is reduced which translates into a lower overall cost and shorter time development from the concept to the final product. Key Words: VTVL, landing gear, structural optimisation, topological optimisation, low mass. 1. INTRODUCTION A number of performance-related innovations are needed for future space transportations systems such as fully reusable launch vehicles [1]. An important subject of study is the development of reusable rockets capable of vertical takeoff and vertical landing (VTVL) to perform different types of missions. Generally in order to achieve the necessary experience, the development starts with concept vehicles at a smaller scale. From the beginning, low mass was a real target for aerospace and space vehicles. It is desirable that the available material to be distributed as efficiently as possible in order to fulfill its intended purpose. The concept of structural of optimization was born from this necessity. That means finding the best solution considering a group of already established criterions. The major challenge faced by researchers in structural optimisation is to develop methods that are suitable for use with such software packages. Another major challenge is the high computational cost associated with the analysis of many complex real-life problems.