Assessment of the stress state of round and annular cross-section beams made with different tensile and compressive properties materials

At present, there is great interest in carbon-based materials. They have high thermomechanical properties and mass characteristics, are quite technologically advanced. Such materials are widely used in aviation and space technology, for example, for the manufacture of load-bearing elements, beams, frames, as well as aircraft and rocket skin elements. The article considers the stress state of bent beams of circular and annular section made of carbon fiber reinforced plastics. When tested in tension and compression, such materials, called multi-modulus, exhibit different properties. Therefore, for strength calculations, it is necessary to use special strength models. A method is proposed for calculating the bending of beams of circular and annular cross-section made of M46 and IMS-65 carbon fiber reinforced plastics. Their tensile and compressive moduli and corresponding strengths were determined by testing on a ZDM-10 machine with an accuracy of ±1,25%. The examples show that in the calculations it is necessary to take into account the difference in tensile and compression properties, as well as the real position of the neutral axis of the bent beam section.