scholarly journals The effect of thrust force in drilling composite materials using step core-ball drill

2018 ◽  
Vol 185 ◽  
pp. 00016
Author(s):  
Hsing-Ming Teng ◽  
Chung-Chen Tsao
Keyword(s):  
Composite Materials ◽  
Composite Laminates ◽  
Thrust Force ◽  
Weight Ratio ◽  
Composite Plates ◽  
High Strength ◽  
Tool Geometry ◽  
Machining Parameters ◽  
Chip Flow ◽  
Hole Making

Composite materials have gained increasing popularity over the past few decades due to their superior mechanical properties, such as high strength-to-weight ratio, fighting against high temperature and corrosion resistance. The assembly of enormous aeronautical components and structures require the machining of composite materials. Drilling is the most important hole-making process in the final assembly. When drilling composite materials, a number of defects are generating. Delamination caused by drilling thrust has been showed as one of the most problematic defects after drilling composite laminates. With a pressing need for decreased delamination, many studies are turning more and more toward tool geometry and machining parameters. Drilling of composite plates using a step core-ball drill, which is a special drill to improve the chip flow and reduces the thrust force at the exit of hole, is investigated in this study. The experimental results found that the step core-ball drill was efficient in drilling of carbon fiber reinforced plastic (CFRP) and did not produce loading on the drill exit at the proper drilling conditions. The results obtained from this study feeding back for fundamental research efforts could steer future studies on the drilling composite materials in the most promising direction.

The Effect of Thrust Force in Drilling Composite Materials Using a New Step Core-Ball Drill

2020 ◽  
Vol 830 ◽  
pp. 77-84
Author(s):  
Hsing Ming Teng ◽  
Ming Chang Wu ◽  
Jin Yi Kao ◽  
Chun Yao Hsu ◽  
Chung Chen Tsao
Keyword(s):  
Composite Materials ◽  
Composite Laminates ◽  
Thrust Force ◽  
Composite Plates ◽  
High Strength ◽  
Tool Geometry ◽  
Lower Weight ◽  
Final Assembly ◽  
Chip Flow ◽  
Metal Materials

Compared with conventional metal materials, composite materials can sustain more loads under lower weight and lower space, which is more suitable to use in high strength environment for structure parts application in aerospace, military, transportation and leisure. The enormous aeronautical components and structures of composite materials require assembly and machining. Drilling is the most important making-hole process in the final assembly. However, conventional drill cannot avoid delamination in drilling composite materials effectively depending on tool geometry only. Delamination caused by drilling thrust has been showed as one of the most problematic defects after drilling composite laminates. Drilling of composite plates using a new step core-ball drill (NSCBD), which is a special drill to improve the chip flow and reduces the thrust force (delamination) at the exit of hole, is studied and compared to the traditional step core-ball drill (TSCBD). The thrust force of new step core-ball drill in drilling composite materials was investigated in this study. The theoretical analysis and experimental results show that the NSCBD can improve the thrust force (delamination) and efficiency than TSCBD in drilling composite materials.

Experimental Analysis for the Effect of Impactor Geometry on Carbon Reinforced Composite Materials

2017 ◽  
Vol 25 (9) ◽  
pp. 677-682 ◽  
Author(s):  
Faruk Elaldi ◽  
Busra Baykan ◽  
Can Akto
Keyword(s):  
Composite Materials ◽  
Carbon Fibre ◽  
Composite Plates ◽  
High Strength ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Area ◽  
Reinforced Composite ◽  
Contact Surfaces ◽  
The Impact

For the last three decades, composites have become very preferable materials to be used in the automotive industry, structural parts of aircraft and military systems and spacecraft, due to their high strength and modulus. Composite materials are sometimes exposed to invisible or visible damage due to impact loading during their service life. In this study, the effect of impactor geometry with four different contact surfaces on woven carbon fibre-reinforced composite plates having three different thicknesses are investigated. In the first stage, composite plates were manufactured with the ply orientations of [45/-45/0/90/45/-45]2s, [45/-45/0/90/45/-45]3s, [45/-45/0/90/45/-45]4s based on conventional usage. In the second stage, carbon fibre-reinforced composite test panels were exposed to low velocity impact tests to obtain force-time, energy-time and force-displacement curves. Finally, semi and full penetration of composite panels and damage magnitude were determined. It was found that the impactor geometries with lower contact surfaces such as conical and ogive types were much more penetrative on composite plates than the other geometries, but they caused larger damage area in the vicinity of the impact point.

Delamination-Free Drilling of Composite Laminates

1994 ◽  
Vol 116 (4) ◽  
pp. 475-481 ◽  
Author(s):  
S. Jain ◽  
D. C. H. Yang
Keyword(s):  
Composite Laminates ◽  
Thrust Force ◽  
Tool Geometry ◽  
Elliptical Plate ◽  
Hole Quality ◽  
Drilling Operation ◽  
Twist Drills ◽  
Drill Tool

Composite laminates in significant numbers are rendered unacceptable due to delamination that occurs during the drilling operation. Thrust generated during the drilling operation is identified as responsible for delamination. Expressions developed for critical thrusts and critical feed rates, by modeling the delamination zone as an elliptical plate in unidirectional laminates, appear to be fairly accurate. It has been demonstrated that the critical thrusts and feed rates obtained for unidirectional laminates can be conservatively used for multi-directional laminates. With regard to the tool geometry, the chisel edge width appears to be the single most important factor contributing to the thrust force and hence delamination. A diamond-impregnated tubular drill tool was designed and tested. This tool resulted in a much smaller thrust and much better hole quality as compared with the standard twist drills.

Multi-Objective Optimization on Drilling of Titanium Alloy (Ti6Al4V)

2013 ◽  
Vol 763 ◽  
pp. 29-49 ◽  
Author(s):  
A. Prabukarthi ◽  
V. Krishnaraj ◽  
M. Senthil Kumar
Keyword(s):  
Titanium Alloy ◽  
Thrust Force ◽  
Optimization Technique ◽  
Weight Ratio ◽  
High Strength ◽  
Hole Diameter ◽  
Machining Process ◽  
Multi Objective ◽  
Titanium Alloy Ti6al4v ◽  
Exit Burr

Titanium alloys present superior properties like resistance to corrosion, high strength to weight ratio etc, but possess poor machinability. Titanium alloy Ti-6Al-4V is the most commonly used titanium alloy in aerospace and medical device industries. Titanium and its alloys are notorious for their poor thermal properties and are classified as difficult-to-machine materials. Drilling is an important machining process since it is involved in nearly all titanium applications. It is desirable to develop optimized drilling processes for Ti and improve the hole characteristics such as hole diameter, circularity and exit burr of currently available processes. Due to the low machinability of the alloys under study, selecting the machining conditions and parameters is crucial. The range of spindle speed and feed rate, which provide a satisfactory tool life, is very limited. The hole quality (hole diameter and circularity), thrust force, torque and exit burr were evaluated at various spindle speeds, feed rates combinations. The optimized parameter is chosen using the multi-objective weighted sum optimization technique.

Impact of the Harsh Environment on E-Glass Epoxy Composite

2019 ◽  
Author(s):  
Amir Hussain Idrisi ◽  
Abdel-Hamid Ismail Mourad ◽  
Beckry Abdel-Magid ◽  
Mohammad Mozumder ◽  
Yaser Afifi
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Oil And Gas ◽  
Epoxy Composite ◽  
Uv Light ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Harsh Environment ◽  
Sustained Loads

Abstract Composite materials are being used in many industrial applications such as automobile, aerospace, marine, oil and gas industries due to their high strength to weight ratio. The long-term effect of sustained loads and environmental factors that include exposure to UV light, temperature, and moisture have been under investigation by many researchers. The major objective of this study is to evaluate the effects of harsh environment (e.g. seawater and high temperature) on the structural properties of E-glass epoxy composite materials. These effects were studied in terms of seawater absorption, permeation of salt and contaminants, chemical and physical bonds at the interface and degradation in mechanical properties. Samples were immersed in seawater at room temperature (23°C), 65°C and 90°C for the duration of 6 months. Results show that seawater absorption increased with immersion time at 23°C and 65°C, whereas the weight of the specimens decreased at 90°C. The moisture causes swelling at 23°C and 65°C and breakdown of chemical bonds between fiber and matrix at 90°C. It is observed that high temperature accelerates the degradation of the E-glass epoxy composite. At 90°C, the tensile strength of E-glass epoxy sharply decreased by 72.92% but no significant change was observed in modulus of elasticity of the composite.

scholarly journals STRENGTH PREDICTION OF DIFFERENT ORIENTATION UNIDIRECTIONAL GLASS FIBER LAP JOINTS

2012 ◽  
pp. 278-282
Author(s):  
R. SANTOSH ◽  
B. KIRAN
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Glass Fiber ◽  
Structural Design ◽  
Software Package ◽  
Weight Ratio ◽  
High Strength ◽  
Lap Joints ◽  
Suitable Alternative ◽  
Robot Systems

Composite materials have made way to various fields, including aerospace structures, underwater vehicles, automobiles and robot systems. Due to the high strength to weight ratio of composites, they serve as a suitable alternative to metals, therefore making the need for a reliable database of structural design more important. Most of the modern civilian and military aircraft use composite materials for their primary structural components (in addition to metals). One of the key areas in composite structural design involves the tensile strength of joints. In the present work, the lap joints fabricated from different orientations of GFRP (Glass fiber reinforced polymer) specimens are subjected to tensile test. The effect of fibre orientation on the tensile strength of lap joint is investigated both experimentally and computationally using conventional software package. The experimental results are compared with FEA using conventional software package ANSYS.

Optimum Design of Composite Pressure Vessel Based on 3-Dimensional Failure Criteria

2019 ◽  
Author(s):  
J. Sakai ◽  
Y. H. Park
Keyword(s):  
Optimum Design ◽  
Pressure Vessel ◽  
Composite Laminates ◽  
Three Dimensional ◽  
Weight Ratio ◽  
High Strength ◽  
Failure Criteria ◽  
Pressure Vessels ◽  
Fiber Reinforced ◽  
3D Elasticity

Abstract Anisotropic composite cylinders and pressure vessels have been widely employed in automotive, aerospace, chemical and other engineering areas due to high strength/stiffness-to-weight ratio, exceptional corrosion resistance, and superb thermal performance. Pipes, fuel tanks, chemical containers, rocket motor cases and aircraft and ship elements are a few examples of structural application of fiber reinforced composites (FRCs) for pressure vessels/pipes. Since the performance of composite materials replies on the tensile and compressive strengths of the fiber directions, the optimum design of composite laminates with varying fiber orientations is desired to minimize the damage of the structure. In this study, a complete mathematical 3D elasticity solution was developed, which can accurately compute stresses of a thick multilayered anisotropic fiber reinforced pressure vessel under force and pressure loadings. A rotational variable is introduced in the formalism to treat torsional loading in addition to force and pressure loadings. Then, the three-dimensional Tsai-Wu criterion is used based on the analytical solution to predict the failure. Finally, a global optimization algorithm is used to find the optimum fiber orientation and their best combination through the thickness direction.

Surface Topography and Kerf Study of Nimonic 80A Using Wire-Cut EDM

2014 ◽  
Vol 808 ◽  
pp. 35-41 ◽  
Author(s):  
Amitesh Goswami ◽  
Jatinder Kumar
Keyword(s):  
Surface Topography ◽  
Process Parameters ◽  
Electrical Discharge Machining ◽  
Weight Ratio ◽  
High Strength ◽  
Machining Parameters ◽  
Influence Of Process Parameters ◽  
Nimonic 80A ◽  
Pulse On Time ◽  
Pulse Off Time

Nimonic-80A is a nickel based super alloy which is specifically used in aerospace industry for its high strength to weight ratio and corrosion resistance. This paper presents the influence of process parameters of wire cut Electrical Discharge Machining (WEDM) during the machining of Nimonic 80A with brass wire as electrode and optimization of machining parameters on kerf width. Process parameters (pulse-on time, pulse-off time, peak current, spark gap set voltage, wire feed and wire tension) have been investigated using L27orthogonal array. With the assistance of Taguchi quality design, ANOVA and F-test, significant parameters affecting the kerf have been identified. The surface topography of machined samples has been studied in correlation with the rate of input energy into the spark.

Effects of Feedrate and Chisel Edge on Delamination in Composites Drilling

1993 ◽  
Vol 115 (4) ◽  
pp. 398-405 ◽  
Author(s):  
S. Jain ◽  
D. C. H. Yang
Keyword(s):  
Composite Laminates ◽  
Thrust Force ◽  
Plate Theory ◽  
Tool Geometry ◽  
Laminated Plate ◽  
Elliptical Plate ◽  
Time Optimal ◽  
Critical Thrust Force ◽  
Clamped Edges ◽  
Central Load

Delamination accompanied with the drilling of composite laminates has been recognized as a major problem. An analytical model is established to predict critical thrust force and critical feedrate at which the delamination crack begins to propagate. For unidirectional composites, the delamination zone is modeled as an elliptical plate, with clamped edges and subjected to a central load. Based on fracture mechanics, laminated plate theory and cutting mechanics, expressions are developed for critical thrusts and critical feedrates at which delamination is initiated at different ply locations. This model has been verified by experiments. A variable feedrate strategy is formulated based on this model, which avoids delamination while drilling in a time-optimal fashion. In addition, the need to modify tool geometry to avoid delamination is highlighted. Chisel edge width has been identified as an important factor contributing to the thrust force and hence delamination.

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