Kun Cai

Bio: Kun Cai is an academic researcher. The author has contributed to research in topics: Topology optimization. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

A New Construction Method for a LightweightSubmerged Radial Gate

Abstract: A new design method in hydraulic engineering is presented for the construction of a lightw eight submerged radial gate (SRG) with two vertical arms. In the analysis, the structure is decomposed into several main components and each component is shaped using a topology optimization approach. In particular, a SRG can be divided into three major parts: the water-retaining face plate, the support frame, and the arms. The whole design process for the SRG generally includes five steps: (1) the optimal position of arms is determined in terms of avoiding bending moment of arm adjacent to the support frame; (2) using the topology optimization method, the shape of each arm is determined subject to the symmetry condition with respect to the whole structure; (3) a frame made of horizontal and vertical ribs is constructed to support the face plate; (4) the new radial gate is assembled based on these optimized components, e.g., two arms, the face plate and its support frame; and (5) the sizes of these components are verified using size optimization by considering the stiffness and strength of the new structure under a critical loading condition. To show the validity of the method, a traditional SRG in a real project is adopted as an example and is redesigned using the present method. The evaluation result shows that the new structure is about 27% lighter than the original. At the same time, the mechanical properties of the SRG are significantly improved.

Optimal layout of multiple bi-modulus materials

Abstract: A modified solid isotropic material with penalization (SIMP) method is proposed for solving layout optimization problems of multiple bi-modulus materials in a continuum. In the present algorithm, each bi-modulus material is replaced by two distinct isotropic materials to avoid structural reanalysis for each update of the design domains. To reduce the error in local stiffness due to the material replacement, the modification factor of each finite element is calculated according to the local stress state and the moduli used in the previous structural analysis. Three numerical examples are considered to demonstrate the validity and applicability of the present approach. Numerical results show that the final layout of materials is determined by factors that include the moduli difference of each bi-modulus material and the difference among material moduli.

A New Design of a Hydraulic Steel Radial Gate with Two Oblique Arms by Topology Optimization

Abstract: A hydraulic steel radial gate (SRG) with two oblique arms is designed by using topology optimization and size optimization. Topology and size optimization are carried out by using CAD software, e.g., Hyperworks. In the current design, the SRG is initially considered to have three main components, i.e., the arms, the supporting frame of arms and a panel for water retaining. To give a better design of these components, e.g., arms and its supporting frame, topology optimization is adopted. By topology optimization method, the shape of arm and the supporting frame are obtained. As construction of the new SRG is reconstructed by the components obtained, the stiffness, strength and stability of the new SRG is checked and some sizes of components in SRG are readjusted by using size optimization. The final design of the SRG is around 24% lighter than the traditional design whilst the safety of the new design is much better.