The Applications of Shape-Changing Rigid Body Mechanisms in Arts and Engineering

Design of shape-changing or shape-morphing machines is an area of growing importance. Shape-change can potentially be applied soon to vary the cross section of a wing, create wind or liquid flow control by morphing shapes to locally influence downstream fluid behavior, or vary the size of a car seat to meet a wider array of human anthropometric needs. Rigid body shape-change mechanisms offer many advantages including the high capacity to endure substantial loads while achieving large displacements. Their design techniques are also well-established. The goal of this research project is to develop the synthesis theory to address planar rigid-body shape-change where significant differences in arc length define the problem. A MATLAB-based software was developed to facilitate visual assessment of the process and results. Lastly, this paper illustrates several mechanization examples that apply the segmentation process, and the fundamental mechanism synthesis to guide the motion of the chain of rigid bodies to progress to the subsequent positions

A Note on Redesign Material Substitution and Topology Optimization in a Lightweight Robotic Gripper

The gripper is required because it is the portion of the robot that makes direct contact with the object being grasped. It should weigh as little as possible without compromising functionality or its performance. This study aims to reconsider the construction of a lightweight robotic gripper by modifying the gripper's materials and topology. Using the finite element (FE) method, several types of gripper materials were evaluated for static stress. On the basis of the results of the FE analysis, the optimal material candidate was chosen using the weighted objective method. Using the Fusion 360 software, the topology of the selected material was then optimized in an effort to achieve the 40% weight reduction’s objective. In addition, the suggested optimized geometry is then fine-tuned so that it can be manufactured as efficiently as possible. The final step in the validation of the robotic gripper's design was stress static analysis. The revised gripper design has a mass of 0.08 kg, a reduction of 94% from the original mass, and a safety factor of 3.67%, which satisfies the desired level of performance for the robotic gripper. Utilizing different materials and optimizing the gripper's topology can significantly reduce the overall mass of a robotic gripper. &nbsp

Comparison of Soot Particle Movement based on Crank Angle

In a diesel engine, soot was produced due to incomplete fuel combustion in a combustion chamber. Some of this soot sticks to the cylinder wall and interferes with lubricant oil. This soot causes the lubricant oil to contaminate and this increases its viscosity. Contamination of lubricant oil is one of the major causes of engine wear. Therefore, the focus of this study is on soot movement in diesel engine that is the initial step to avoid contamination of lubricant oil. This work uses the data of the formation of soot particles from Kiva-3 v obtained from previous investigation and then simulated it by a Matlab routine. Kiva-3 v produced velocity vectors of the soot, fuel, temperature, pressure and others. Matlab routine uses trilinear interpolation and fourth order Runge Kutta method in order to calculate soot movement in a combustion chamber. In addition, the influence of drag force is considered in the calculation to achieve a higher accuracy. The objective of this study is to compare soot particle movement between 8° ATDC and 18° ATDC. Results show that 8° ATDC has a high risk to contaminate lubrication oil in certain location compare to 18° ATDC

THE EFFECT OF DIESEL AND BIO-DIESEL FUEL DEPOSIT LAYERS ON HEAT TRANSFER

The adhesion of deposits on the combustion chamber wall surface affecting the heat transfer process in an engine that cause engine knock, increase NOx and increase soot generation during the combustion process.  The effect will be more significant when utilizing bio-diesel fuel due to its higher density and viscosity. Thus, this study is intended to investigate the effect of diesel and bio-diesel fuels deposit layers on heat transfer. In this study, deposit layer of diesel fuel (DF) and 5% palm oil based bio-diesel fuel blends (B5) were prepared for surface temperature at 250°C and 357°C by using a hollow cylinder heater. Then, the hollow cylinder covered with deposit layer in its inner surface was inserted in a heat transfer chamber apparatus to investigate its effect on heat transfer to surrounding. Deposit layer for DF that was prepared at surface temperature of 357°C was able to act as insulator which prevents the heat from transferring to the surrounding compared to deposit layer formed at lower surface temperature. However, deposit layer of B5 prepared at surface temperature of 250°C have better insulator properties compared to DF at the same surface temperature