New biomimetic approach to the aircraft wing structural design based on aeroelastic analysis

This paper presents a new biomimetic approach to the structural design. For the purpose of aircraft wing design the numerical environment combining simultaneous structural size, shape, and topology optimization based on aeroelastic analysis was developed. For the design of aircraft elements the optimization process must be treated as a multi-load case task, because during the fluid structure interaction analysis each step represents a different structural load case. Also, considering different angles of attack, during the CFD computation each result is considered. The method-specific features (such as domain independence, functional configurations during the process of optimization, and multiple load case solution implemented in the optimization scenario) enable the optimal structural form. To illustrate the algorithm functionality, the problem of determining the optimal internal wing structure was presented. The optimal internal wing structure resulting from aeroelastic computation with different angles of attack has been presented.

The Determination of Condition Met by Boom System Working in Safety Based on Multiple Load Case Analysis

Loads subjected by the boom system on the concrete pump are so complex, that fatigue cracks or fatigue fractures appear, which may lead to loss of property and casualty. However, when the concrete pump is functioning in safe condition, the damage of the boom system is reduced, thereby preventing the accidents. In order to select safe working conditions, a boom system of 37m concrete pump as research object should be adopted. The finite element analysis is carried out on the boom system based on MSC. Patran and Nastran, with regularly varying degrees, and changing trends of the maximum stresses subjected by booms with the change of degrees of booms, attained a safe condition of the boom system. Finally, taking the four kinds of typical foundation casting working conditions as example, the feasibility of using this condition to determine the safe working condition has been verified.

Topology optimization of trusses using bars exchange method

The algorithm of optimization of trusses is presented in the paper, where for topology optimization the bars exchange method is used. In the first case, the problem aimed at cost minimization with a constraint set on global stiffness is formulated. In the second case, the problem of minimizing the cost function subjected to stress and cross-sectional area constraints is discussed and here the multiple-load case is taken into consideration. The conditions for introduction of topology modification and its acceptance are specified. The paper is illustrated with three examples.