The Topology Optimization Of Wing Rib Based On The Development Of The MSC.Patran

An aircraft wing is composed of spars, stringers,skins and ribs. The spars, stringers and skins arethe main load carrying members of the wing. The ribs are used to keep the shap of the wing and onlycarry little of the global bend and twist loads acting on the wing. However, the weight of ribs makesup significant fractions of the total weight of the wing box, about8%to12%. So it is very necessaryto use some optimization method to reduce the weight of the ribs..Topology optimization that is oneof the major subjects of optimization research up to date, usually needs to determine many moreparameters than size optimization and shape optimization.However, it can be obtained more benifit.So topology optimization is an effective method to reduce the weight of the ribs.In this article, a SIMP interpolation model based on the alterable density method is formulated,which refers to the minimal compliance as objective and subjects to structural volume and is solvedusing the optimization criterion method. An adaptive volume constraint method based on the stresslevel of the element is proposed to overcome the shortcoming of the SIMP method that can’t respondthe stress level of the element directly. The globalization of stress constraints method based on ICMmethod is also be formulated, which refers the minimal weight as the object function and admissiblestress of the element as the constraints. An dual-quadratic programming method is used to solve theproblem.The topology optimization modules of the adaptive volume constraint method and globalizationof stress constraints method are developed on the MSC.Patran using the Patran Command Language(PCL). The value of the typical loads on the wing box rib are calculated using the engineeringprediction method. In this article the adaptive volume constraint method and globalization of stressconstraints method is used to the topology optimization of the rib for the first time. Finally an optimalconfiguration is get based on the full stress design throw the to methods.The studies indicate that therib based on the optimal topology configuration that is satisfied with the stability requirements ismore lighter.