Topology Optimization Design Of Micro Hard Disk Drive Actuating Arm

Accompany with the fast development of computer and electronic technologies, small size and large capacity hard disk storage technique gains widely attention. Micro hard disk drives were widely used in many products and equipments with their advantages such as large capacity, long life, high-speed transferring and shockproof. The key techniques of micro hard disk drive are mostly focus on read and write data efficiently from the disk. Therefore, how to design the actuating arm structure properly which drives the magnetic recording head becomes a very important topic. From the other side, the topology optimization provides a possibility for designing lighter and better actuating arm.The actuating arm of micro hard disk drive was studied carefully in this thesis, including its structure, working environment and motion features. Two topology optimization models were formulated. The statics and free vibration were described as the objective functions in these models. One was based on the static compliance of actuating arm, another one was based on modal analysis of the free vibration and the last one was based on Multi-objective optimization of hard disk drive actuating arm.In this thesis, after a brief introduction was proposed in Chapter 2, initial design domains and two topology optimization mathematical models were formulated, which based on static analysis and modal analysis techniques separately. The sensitivities of objective functions and constraints were derived and then there was a discussion about numerical issues in topology optimization.Furthermore, the codes were writing based on MATLAB. The ANSYS was treated as a finite element solver for solving analysis part in topology optimization problems. It provided information in program iterations in order to evaluate the value of objective function and sensitivities. The result could be got when the iteration converged. At last, two types of problems were solved and four topology plots were achieved. The new finite element models were constructed via the topology plots and analysis were made.This thesis provided a detail analysis for micro hard disk drive. Based on it, static compliance and eigenvalues were used as objective value in the topology optimization models. In order to tracking eigenvalues in implement, a technique called tracking mode was employed. The standard optimality criteria (OC) method and a new material updating method based on sorting sensitivities were engaged separately in solving these two topology optimization problems. The solutions validation was discussed in Chapter 5.