Rigid Dynamic Analysis Research Articles

Investigation on form-preserving polishing of side-wall surfaces via an active fluid jet.

In recent years, extensive research and development have been conducted on an active fluid jet (AFJ) polishing-based post-polishing process aimed at removing periodic marks from diamond-turned surfaces. This cost-effective method demonstrates its machining capability across a wide range of materials. Notably, it excels in preserving the form accuracy during the post-polishing process for traditional optics, allowing for the attainment of high-precision shape and an ultra-smooth texture. However, the challenge arises when attempting to maintain form preservation on diamond-cut surfaces located on the side-walls of structures due to non-uniform material removal. This limitation significantly restricts its application in advanced opto-mechanical systems, including monolithic multi-surface workpieces. Therefore, this paper systematically investigates the form-preserving capability of AFJ polishing for side-wall surfaces through multi-scale analysis. The micromachining characteristics of the diamond-cut surface are elaborated upon using elastic-plastic theory, and the impact of polishing parameters on form preservation is studied at the microscopic scale. Furthermore, at the macroscopic scale, a simulation model of the AFJ polishing process is established based on fluid-structure interaction (FSI) analysis and rigid dynamic analysis. To validate the proposed theory, a series of tests are conducted. Theoretical and experimental results indicate that non-uniform material removal occurs in the contact area between the tool and the workpiece due to the influence of gravity, thereby hindering the form-preservation polishing process. Building upon the simulation model, a new AFJ tool is designed and optimized to enhance the form-preserving capability of AFJ post-polishing for side-wall surfaces. Experimental results confirm that the innovative AFJ tool uniformly eliminates the periodic marks on diamond-cut surfaces. The theory and methodology presented in this work have broad applicability to various form-preservation post-polishing processes on diamond-cut surfaces.

Design, Analysis and Development of Mobile Robot with Flip-Flop Motion Ability

Abstract In this study, a mobile robotic system having the ability for flip-flop motion was designed and analyzed using CAD (Computer Aided Design) and CAE (Computer Aided Engineering) methods. The robot was designed to manufacture with FDM (Fused Deposition Modeling) technique that is most common RP (Rapid Prototyping) methods. System was developed with 4 wheels and each wheel was connected to body with 4 motional legs. For the suspension and flip motion ability legs and body were connected to each other with 2 dashpots as up and down sides. Dynamic and structural analyses were conducted to determine the power and torque requirements of the system that can be used for actuator selection, to obtain the energy storage on the suspension system for flip-flop motion and to check the structural strength of the robot’s components. Ansys Rigid Body Dynamics and Static Structural tools were used. In the analyses, a concrete road with the length of 1,000 mm and 10° inclinations was created as ground to simulate the real world. Obstacles with the height of 80 mm were placed on different locations on the path of the wheels for the robot. The length of robot and the number of wheels were decreased to one half of the real to ease the analysis. It was obtained from the analyses results that safety factor values for whole body and critical component (suspension legs) were found as almost 2 and 0.8, respectively. From these results, a reinforcement process was required especially for suspension legs. Maximum equivalent stresses were also calculated as 14.7 and 27.2 MPa. From the rigid dynamic analysis, it was observed that the total power requirement of the system was about 300 Watt while it was driven with maximum speed 2m/s.

Drilling and Riveting Agencies Rigid Structural Dynamics Analysis of Virtual Prototype

Based on Pro/E and ADAMS software to establish drill riveting mechanism of virtual prototype, and complete the mechanism of rigid dynamics analysis, obtained the displacement, velocity, acceleration, correlation curve of the stress size, drilling for the further research on the mechanical performance of organizations and riveting optimization provides reference basis.