摘要：An interactive computer aided preliminary design system has been developed mainly for gas turbine engine rotors. The design system covers three parts: disks, shafts and rotor dynamics. A nu- merical optimization package called MPOP is used to minimize the weight of disks, shafts and optimize the arrangement or stiffness of bearings for rigid or flexible rotors subjected to certain constraints of sizes, shapes, stresses, deflections, stiffness and frequencies. Various forms of disks, shafts, rotors and structure-analysing result curves are displayed on the screen. Designer may select, inspect or modi- fy the results interactively. The integrated design of structure, optimization, strength and rotor dynamics has improved design quality and reduced turnaround time during preliminary design phase of gas turbine engine develop- ment. As an example, a real preliminary design of an aeroengine turbine rotor is described.

摘要：Buoy is the structure which is floated on sea surface in order to indicate the presenting obstacle such as reef and shallow sea and to show the direction of sea route to ship during sailing. Generally, the conventional material of buoy is steel and it has some problems. Firstly this steel light buoy has safety risk in case of collision between ship and steel buoy. Secondly steel buoy revealed high corrosion environment of salted water and oxide and corrosion of steel can lead to marine pollution. Thirdly it needs too much maintain cost because of its heavy weight. In this study, in order to overcome these problems we changed the buoy material from conventional steel body to polyethylene body. Polymer buoy body was designed with module type part and it can reduce total weight up to 43.12%. To evaluate the strength of that part, the structure analysis simulation was carried out with respect to stress, displacement, and strain. Maximum stress was 1.667 × 107 N/m2 and it was 25% of yielding stress of base material. Maximum displacement and strain were 3.164 mm and 0.00433353 and they are too small value and in safe range with comparing to total length of body. The stability of polymer buoy body was compared with conventional buoy with respect to center of gravity, center of buoyancy, metacenter, oscillation period, and tilt angle by wind, tidal current, and wave. Every value was improved comparing conventional one and we can get more stable buoy. Therefore the new polymer buoy body could prove its safety and stability.