Parameters optimization of micro drilling process for CFRP using two flute solid carbide drill bit

Today, composites material is an alternative to the metal components in the airliner bodies and structures because of its lightweight material characteristic which can contribute to reducing aircraft fuel consumption. Carbon Fibre Reinforced Polymer (CFRP) has multiple plies of material that is piled together in reinforced laminates component form with different material properties throughout the structure. Micro hole on CFRP panel is required for acoustic panel of an aircraft engine. However, drilling process for CFRP material is typically challenging due to high structural stiffness of the composite, low thermal conductivity of polymer and thermally stable of its carbon fiber. Poor resin areas between adjacent laminated plies are prone to drilling-induced damage such as delamination that compromises the material structural integrity. Delamination always related to thrust force during machining process. It can lead to lower hole accuracy of the drill hole entry and exit. Therefore, the optimum parameter for drilling process such as machine spindle speed and feed rate are essential to improve the quality of the hole as well as increase the tool life span. In order to understand the behaviour of CFRP material during machining process, tribological study using Ball-on-disk (BOD) tester was conducted to evaluate properties of CFRP material towards frictional force and wear rate. As the applied load increase, the average frictional force also increased. The result contributed to the selection of the optimum range of parameter for the micro drilling process. The thrust force during machining and hole accuracy at hole entry and exit are investigated by using variable spindle speed and feed from 8,000 to 12,000 rpm and 0.001 to 0.015 mm/rev, respectively. Hence, from the Taguchi L9 (32) experiment the feed rate of 0.001 mm/rev was eliminated to proceed for the optimization stage due to its’ insignificant impact on the investigated variable. Based on one-way ANOVA results from Taguchi L9 (32) experiments, the significant parameter for thrust force was cutting feed rate with p-value = 0.004, while hole accuracy was analysed by S/N ratio, in which feed rate achieved 1st rank and spindle speed at the 2nd rank for the significant factor. The optimisation and validation of micro-drilling parameters with respect to the thrust force and hole accuracy in machining of CFRP material were subsequently investigated. The experiments were systematically carried out by 2-Level Factorial experiment. The mathematical models for thrust force, 1st hole entry accuracy, 20th hole entry accuracy, 1st hole exit accuracy and 20th hole exit accuracy were developed in this stage. In addition, analysis of variance (ANOVA) was also carried out to check the significance of the models. Three validation experiments are conducted to determine the error percentage of thrust force and hole accuracy. Based on the results, the error was less than 10% for hole accuracy measurements while for thrust force an error of 17.70% was recorded. However, since the desired response for thrust force was to “minimize”, hence the value can be acceptable. The optimum conditions for minimum thrust force and high hole accuracy were found to be at spindle speed of 10,762 rpm and feed rate of 0.01 mm/rev

Optimization Of Square Shape Portable Vacuum Clamping (Square) Based On Machining Parameter

Clamping is a fastening device function to hold or secure the object to prevent movement during process or when applied pressure. There are many types of clamping device available for many purposes. This project purpose is to optimize the vacuum clamping based on the machining parameter. From the previous research that develop the vacuum clamping, the product is continue to use to determine the machining performance of vacuum clamping. However, at that time the target was only to develop a functional prototype and only some testing were done. Therefore, in order to optimize the vacuum clamping surface roughness testing was done using this new clamping device to compare with existing clamping device. The expected result show that vacuum clamping is better. As a conclusion, vacuum clamping can be improved for better use in the future and apply to the manufacturing field

Vehicle Blind Spot Monitoring Phenomenon Using Ultrasonic Sensor

This paper evaluates a conceptualization of Vehicle Blind Spot Monitoring System (VBMS), which performs a more effective approach in eliminating blind spot of the driver. The newly developed smart blind spot monitoring system simply focusing on an advancement of the preceding work, along with compromising user compatibility and cost-effectiveness. Compact design, reliable and low-cost that contributes to a highly affordable safety feature are the flagship of this new system. Components selection is the main role in constructing an inexpensive blind spot detection system in the present work. Thus, Arduino UNO R3 model and HC-SR04 ultrasonic sensors were employed for the VBMS system due to reasonable market price. Plus, the ultrasonic sensor has demonstrated a remarkable performance in the past blind spot detection system application. Concerning easy installation as well as maintenance on any vehicle, the VBMS is designed as a compact device which assembles the main control unit and sensory partsin a single body to be located at the bottom of the side mirror. Meanwhile, the hazard-warning signal is separately located at the passenger compartment for easily visible by the driver. The angle and sensing range of sensors are both adjustable but vital as their projections define the blind spot limit accurately by characterizing low to a high potential hazard. At the end of this work, a complete VBMS functional prototype of has been establish which effective for real traffic on-road experimentation, with various conditions specified (static, various speed, and overtaken). From the data collected, all targets of the present work have been attained regarding monitoring phenomenon shown by the new-built system. Both pros and cons of VBMS are discussed for further improvement ideas on product developmen

Design Improvement Of Fixable Clamping Jig For Milling Machine Based On Surface Roughness

Jigs provide a means of manufacturing interchangeable parts since they establish a relation with predetermined tolerances, between the work and the cutting tool. Jigs are used on drilling, reaming, tapping, milling and tapping. The objective of this project is optimizing and analyse of the fixable clamping jig for milling machine. The method is modified clamp mechanism of the previous jig, optimize the design of the fixable clamping jig for milling machine, and analyse the result of fixable clamping jig in term of surface roughness. The result of the experiment will be evaluated base of surface roughness by using Portable Surface Roughness Tester, SJ-401. Then, the result will compare with current vise result and fixable clamping result. From the results that have get, the average of Ra value using current vise as a clamping method is higher than using fixable clamping as a clamping method which are 3.468 when using current vise and 1.657 when using fixable clamping for Delrin as a work piece. While for aluminum as a work piece, the average of Ra value using current vise as a clamping method is lower than using fixable clamping as a clamping method using current vise is 3.069 compared to using flexible clamping is 5.90

Optimization Of Round Shape Portable Vacuum Clamping Based On Machining Parameters

The aim of this project is to optimize the round shape portable vacuum clamping based on machining parameters. The selected machining parameter is spindle speed, depth of cut and feed rate. The vacuum clamping was tested to evaluate and analyse the result of surface roughness and time setting. The result shows that the portable round shape vacuum clamping is the best clamping system compare with conventional vise in term of setup time. The time is taken for setting the workpiece on the clamping device for vacuum clamping is 13.6 seconds which is faster than conventional vise 54.7 seconds. For surface roughness, the smooth surface is 1.627 µm at 910 RPM of spindle speed. 910 RPM spindle speed is most suitable for machining 0.5mm depth of cut on portable round shape vacuum clampin

Experimental Investigations Towards Hole Accuracy In Micro-Drilling Of Carbon Fibre Reinforced Polymer Material

Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes for metal parts in aircraft and automotive components since they are lighter in weight. However, micro drilling CFRP materials during the assembly process poses various challenges such as low hole accuracy and delamination. Hence, an experiment has been executed to investigate the influence of micro drilling parameters towards hole accuracy. The spindle speed and feed rate are the machining parameters that have been considered in this experiment. Three different optimum parameters have been obtained from previous experiments, involving the spindle speed combinations of 8,000, 10,762 and 11,017 min-1 with a feed rate of 0.01 mm/rev. A drill bit with a diameter of 0.9 mm is used to drill approximately 300 holes. It has been revealed that the combination of the spindle speed of 11,017 min-1 and feed rate of 0.01 mm/rev produce high hole accuracy at the 2nd hole compared to the 300th hole due to the presence of uncut fibres at the 300th hole which have reduced the hole area. Hence, outcome of this research could provide the benefit to the industries in term of manufacturing time and materials expenditur