With the increasing of consumption of sources and the population of mankind on Earth, scientists are looking for an alternative planet in the solar system that can establish the second home for mankind. Previously, Mars has been the center of attention by scientists due to the closer distance to Earth and being similar to that in many aspects. Recently, scientists discovered that there may be a better alternative. Titan, despite its great distance from the Earth, seems like a better planet for the mankind colonization due to its atmosphere that create a shield against the radiation in comparison to Mars' atmosphere that is thin and is not capable to create an adequate shield against radiation. In the previous work, the thermal life of carbon structures on Mars was approximately estimated. The aim of this research is to provide a method to estimate the thermal life of carbon structures on Titan. Carbon structures are currently used in space structures due to their lightweight and strength.

Thermomechanical fatigue is one of the challenges for spacecrafts during space missions. As a result of the extreme temperature variation in space, thermal cycles are created, and due to the imposed mechanical loads to spacecrafts such as engine loads while they turn on and off, mechanical cycles are created. The worst structural fatigue for spacecrafts occurs when both thermal and mechanical cycles happen, simultaneously. The reason is that both thermal and mechanical cycles could cause stress concentration in the spacecraft structure. Therefore, the probability of crack initiation or propagation in the spacecraft structure increases. In this study, for the first time, novel thermomechanical fatigue relations are introduced to evaluate the safety of unidirectional carbon fiber/epoxy composite in the space environment. This composite material has been used in the spacecraft structure due to its lightweight and high strength. Furthermore, with applying thermal fatigue relations, thermally-safe planets, moons, and asteroids in the solar system for unidirectional carbon fiber/epoxy composite are identified.

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In this paper, by applying analytical method and using experimental

This paper studies the flexural behaviour and ductility ratio of reinforced concrete beams made with steel fibres and coarse recycled aggregates (RAs) and strengthened after failure. Eight reinforced concrete beams (of 150 by 200 mm cross-section and 1500 mm span), with various transverse reinforcement spacings, were manufactured and tested. RAs from building demolition were used at 0% and 100% by mass to replace natural aggregates. Furthermore, steel fibres were added to improve the flexural behaviour of the beams at 0% and 2% (by volume). Both shear and flexural failures in a four-point bending test were analysed in specimens with various transverse reinforcement spacings. First, the specimens were tested to failure and then strengthened with a concrete jacket. In these tests, the flexural capacity, maximum displacement at mid-span and ductility before and after strengthening using the concrete jacket were measured. The effects of the steel fibres and of the transverse reinforcement spacing on the flexural behaviour of RA concrete beams, with and without a concrete jacket, were determined. Concrete jacketing is an efficient method for strengthening RA concrete beams, and when steel fibres, RA, and a combination of both were used, the ductility ratio increased by 160, 24 and 146%, respectively.