Punching Force Reduction with Wave-Formed Tools

2007 ◽  
Vol 344 ◽  
pp. 209-216 ◽  
Author(s):  
Jussi A. Karjalainen ◽  
Kari Mäntyjärvi ◽  
Martti Juuso
Keyword(s):  
Cutting Force ◽  
Experimental Work ◽  
Tool Geometry ◽  
Material Strength ◽  
Test Results ◽  
Electro Discharge Machining ◽  
Lateral Forces ◽  
Circular Holes ◽  
Hole Geometry ◽  
Force Reduction

Flat-end tools are the most general types used in sheet metal punching and nibbling. They are geometrically simple and easy to sharpen but, on other hand, their cutting forces are relatively large, and hence the cutting process is frequently noisy. In order to reduce both cutting force and noise tools with one-way or two-way shearing have been utilised. The major drawbacks of these tools are the asymmetry of cutting easily causing non-circular holes with round tools, lateral forces with one-way shearing, excessive forming during cutting and more complex tool geometry to maintain. Here a new geometry for a punch is employed. The shearing edge is a sinus curve with several peaks making the cutting edge circularly symmetric and the phenomenon totally balanced. This means smaller forming forces, particularly in cases when also the radial form is concave. The geometry is without doubt more complex compared to the flat-end tool but rather easy to produce by multi-axis milling and electro-discharge machining. In the current work a set of experimental punches has been designed, manufactured and tested. A simple analytical theory for cutting force has also been derived and compared with the test results. The results show that the new geometry produces very precise hole geometry with a lower cutting force compared to conventional flat-end tools. Of course, more theoretical and experimental work is required to optimise the tool geometry including the tool clearance for each pair of material strength and thickness.

Surface Roughness and Cutting Force Components Evaluation in Hard Turning by Differently Shaped Cutting Tools

2016 ◽  
Vol 862 ◽  
pp. 26-32 ◽  
Author(s):  
Michaela Samardžiová
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Hard Turning ◽  
Cutting Tool ◽  
Single Point ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Cutting Force Components ◽  
Force Components

There is a difference in machining by the cutting tool with defined geometry and undefined geometry. That is one of the reasons of implementation of hard turning into the machining process. In current manufacturing processes is hard turning many times used as a fine finish operation. It has many advantages – machining by single point cutting tool, high productivity, flexibility, ability to produce parts with complex shapes at one clamping. Very important is to solve machined surface quality. There is a possibility to use wiper geometry in hard turning process to achieve 3 – 4 times lower surface roughness values. Cutting parameters influence cutting process as well as cutting tool geometry. It is necessary to take into consideration cutting force components as well. Issue of the use of wiper geometry has been still insufficiently researched.

Experimental Study on Shear Behavior of Perfobond Connector with Boot Shaped Slots

2019 ◽  
Author(s):  
Zhanchong Shi ◽  
Qingtian Su ◽  
Xinyi He ◽  
Quanlu Wang ◽  
Kege Zhou ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Stiffness ◽  
Shear Capacity ◽  
High Shear ◽  
Test Results ◽  
Precise Location ◽  
Construction Problem ◽  
Circular Holes ◽  
New Type ◽  
Push Out

<p>In order to solve the construction problem of perforating rebars’ precise location and it’s getting through the circular holes for the the conventional perfobond connector, a new type of perfobond connector with boot shaped slots was proposed. This new type perfobond connector has the advantage of convenient construction and pricise location. Three groups of push-out tests with nine specimens were carried out to study the shear capacity of the new type perfobond connector. The effect of the number and the spacing of boot shaped slots on failure modes, shear capacity, peak slip and shear stiffness were mainly studied. The test results show that the new type of perfobond connector with boot shaped slots has a high shear capacity and a good ductility, it could be widely applied on the connection between the steel and the concrete structures.</p>

scholarly journals Performance of Volcano-Like Laser Textured Cutting Tools: An Experimental and Simulative Investigation

Lubricants ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 98 ◽  
Author(s):  
Zhengyang Kang ◽  
Yonghong Fu ◽  
Xingyu Fu ◽  
Martin Jun
Keyword(s):  
Cutting Force ◽  
Cutting Tools ◽  
Surface Texturing ◽  
Temperature Fields ◽  
Small Scale ◽  
Rake Face ◽  
Forming Process ◽  
Force Reduction ◽  
And Performance ◽  
Distribution Of Stress

In recent years, surface texturing in micro-scale has been attempted on the surface of cutting tools for multiple purposes, e.g., cutting force reduction, prolonging life-span, anti-adhesion, etc. With respect to machinability and performance, micro-groove texture (MGT) has dominated in this field compared to other textured patterns. In this study, a novel volcano-like texture (VLT) was fabricated on the rake face of cemented carbide inserts (WC-Co, YG6) by fiber laser. The following cutting experiment tested the flat, MGT and VLT tools in turning aluminum alloy 6061. The effects of coolant and cutting conditions were investigated. In addition, a validated FEM model was employed to explore the distribution of stress and temperature fields in the tool-chip interface. The initial forming process of adhesion layer on rake face was investigated as well. The results indicated that lower cutting force and less adhesion can be achieved by small scale VLT. This study not only introduced VLT on cutting tools but also revealed its comprehensive performance.

Statistical Cutting Force Model for Orthogonal Cutting of Polytetrafluoroethylene (PTFE) Composites

2013 ◽  
Author(s):  
Felicia Stan ◽  
Daniel Vlad ◽  
Catalin Fetecau
Keyword(s):  
Friction Coefficient ◽  
Cutting Force ◽  
Feed Rate ◽  
Normal Force ◽  
Polynomial Regression ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Tool Geometry ◽  
Force Model

This paper presents an experimental investigation of the cutting forces response during the orthogonal cutting of polytetrafluoroethylene (PTFE) and PTFE-based composites using the Taguchi method. Cutting experiments were conducted using the L27 orthogonal array and the effects of the cutting parameters (feed rate, cutting speed and rake angle) on the cutting force were analyzed using the S/N ratio response and the analysis of variance (ANOVA). Statistical models that correlate the cutting force with process variables were developed using ANOVA and polynomial regression. The variation of the apparent friction coefficient was analyzed with respect to tool geometry and the cutting process. The results indicated that cutting and thrust forces increase with increasing feed rate, and decrease with increasing rake angles from negative to positive values and increasing cutting speed. A power law relationship between the apparent friction coefficient and the normal force exerted by the chip on the tool-rake face was identified, the former decreasing with an increasing normal force.

scholarly journals Analysis of chip formation and cutting forces in end milling AISI D2 tool steel with different cutting tool geometries

2018 ◽  
Vol 178 ◽  
pp. 01016
Author(s):  
Irina Beşliu ◽  
Dumitru Amarandei ◽  
Delia Cerlincă
Keyword(s):  
Cutting Force ◽  
Tool Steel ◽  
Chip Formation ◽  
Cutting Forces ◽  
Cutting Tool ◽  
End Milling ◽  
Great Influence ◽  
Tool Geometry ◽  
Aisi D2 ◽  
Aisi D2 Tool Steel

The purpose of this study was to investigate and establish the correlations between milling tool geometry, cutting conditions, as input factors and the cutting forces variations and chips formation, as output factors when end milling of AISI D2 tool steel. The experiments were carried out using a Taguchi design array. The chip shape and microstructure and cutting force components were analyzed. The results of the study show that the cutting tool geometry has a great influence over segmented chip formation mechanism and cutting force levels.

Model-based sensitivity analysis of machining-induced residual stress under minimum quantity lubrication

2015 ◽  
Vol 231 (9) ◽  
pp. 1528-1541 ◽  
Author(s):  
Xia Ji ◽  
Steven Y Liang
Keyword(s):  
Residual Stress ◽  
Sensitivity Analysis ◽  
Cutting Force ◽  
Cutting Temperature ◽  
Minimum Quantity Lubrication ◽  
Cutting Parameters ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Mixture Ratio ◽  
Minimum Quantity

This article presents a sensitivity analysis of residual stress based on the verified residual stress prediction model. The machining-induced residual stress is developed as a function of cutting parameters, tool geometry, material properties, and lubrication conditions. Based on the residual stress predictive model, the main effects of the cutting force, cutting temperature, and residual stress are quantitatively analyzed through the cosine amplitude method. The parametric study is carried out to investigate the effects of minimum quantity lubrication parameters, cutting parameters, and tool geometry on the cutting performances. Results manifest that the cutting force and residual stress are more sensitive to the heat transfer coefficient and the depth of cut, while the cutting temperature is more sensitive to the cutting speed. Large maximum compressive residual stress is obtained under a lower flow rate of minimum quantity lubrication, small depth of cut, and the proper air–oil mixture ratio. This research can support the controlling and optimization of residual stress in industrial engineering by strategically adjusting the application parameters of minimum quantity lubrication.

Minimization of Ovality of Circular Holes in Drilling Process

2015 ◽  
Vol 799-800 ◽  
pp. 393-396
Author(s):  
Parth Pandya ◽  
Vaibhav Shah ◽  
Ahamed H.M.S. Parvezsh ◽  
Prakash R. Apte
Keyword(s):  
Automobile Industry ◽  
Parametric Design ◽  
Angular Position ◽  
Drilling Process ◽  
Hole Center ◽  
Circular Holes ◽  
Hole Geometry ◽  
High Level ◽  
Aforementioned Factor ◽  
Subsequent Failure

In drilling and boring process, the relief in clamping stress causes deformations that cause variations in the geometry of the drilled hole. In automobile industry, when such holes are used to hold gear systems or rods in place, this variation in geometry leads to poor fitting and subsequent failure. To avoid this, high level accuracy is required which is both expensive and time-consuming. Therefore, a high percentage of such drilled parts are rejected in industry. The present paper addresses this problem by characterizing the variations in hole geometry as a function of clamping force, hole diameter, hole eccentricity (distance of hole-center from center of drilled face) and angular position of hole with respect to clamp location. The analysis result quantifies the comparative effect of each aforementioned factor on hole geometry variation. Taguchi Method based Design of Experiments using L25 orthogonal array has been used for performing the parametric design to arrive at the best settings of the 4 parameters. The optimal settings minimize ovality and displacement of the hole-center, and thus increase hole-fitting and its reliability against manufacturing variability.

Development of Seismic Force Reduction and Displacement Amplification Factors for Autoclaved Aerated Concrete Structures

2006 ◽  
Vol 22 (1) ◽  
pp. 267-286 ◽  
Author(s):  
Jorge L. Varela ◽  
Jennifer E. Tanner ◽  
Richard E. Klingner
Keyword(s):  
Reduction Factor ◽  
Test Results ◽  
Lateral Loads ◽  
Autoclaved Aerated Concrete ◽  
Laboratory Test Results ◽  
Seismic Force ◽  
Force Reduction Factor ◽  
Aerated Concrete ◽  
Hysteretic Characteristics ◽  
Force Reduction

This paper addresses the development and application of a rational procedure to select the seismic force reduction factor ( R) and the displacement amplification factor ( Cd) for the design of autoclaved aerated concrete (AAC) structures. The values of R and Cd are proposed based on a combination of laboratory test results and numerical simulation. The test results are obtained from 14 AAC shear-wall specimens tested under simulated gravity and quasi-static reversed cyclic lateral loads. Analytical responses are predicted using nonlinear analysis models whose hysteretic characteristics are based on the experimentally observed responses. Using an iterative procedure, typical AAC structures are designed using successively larger trial values of the factor, R, until the structure's response (either ductility or drift) exceeds the experimentally determined capacity. A lower fractile of those critical values, modified for probable structural overstrength, is taken as a reasonable value of 3 for R. Using an analogous procedure, a reasonable value of Cd is determined as 3. These values will undoubtedly be refined based on field experience, just as they have been for other structural systems.

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