Effect of Tightening Speed on the Torque-Tension and Wear Pattern in Bolted Connections

2006 ◽  
Author(s):  
Sayed A. Nassar ◽  
Ramanathan M. Ranganathan ◽  
Saravanan Ganeshmurthy ◽  
Gary C. Barber
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Surface Roughness ◽  
Initial Level ◽  
Zinc Coating ◽  
Optical Microscope ◽  
Wear Pattern ◽  
Highly Sensitive ◽  
Contact Surfaces ◽  
Scanning Electron

This experimental study investigates the effect of tightening speed and coating on both the torque – tension relationship and wear pattern in threaded fastener applications. The fastener torque – tension relationship is highly sensitive to normal variations in the coefficients of friction between threads and between the turning head and the surface of the joint. Hence, the initial level of the joint clamp load and the overall integrity and reliability of a bolted assembly is significantly influenced by the friction coefficients. The effect of repeated tightening and loosening is also investigated using M12, Class 8.8, fasteners with and without zinc coating. The torque – tension relationship is examined in terms of the non-dimensional nut factor K. The wear pattern is examined by monitoring the changes in surface roughness using a WYKO optical profiler and by using a LECO optical microscope. A Hitachi S-3200N Scanning Electron Microscope (SEM) is used to examine the contact surfaces, under the fastener head, after each tightening/loosening cycle. Experimental data on the effect of variables and the tightening speed, fastener coating and repeated tightening on the nut factor are presented and analyzed for M8 and M12, class 8.8, fasteners.

Effect of Tightening Speed on the Torque-Tension and Wear Pattern in Bolted Connections

2006 ◽  
Vol 129 (3) ◽  
pp. 426-440 ◽  
Author(s):  
Sayed A. Nassar ◽  
Saravanan Ganeshmurthy ◽  
Ramanathan M. Ranganathan ◽  
Gary C. Barber
Keyword(s):  
Experimental Data ◽  
Initial Level ◽  
Zinc Coating ◽  
Optical Microscope ◽  
Bolted Joints ◽  
Load Estimation ◽  
Wear Pattern ◽  
Highly Sensitive ◽  
Contact Surfaces ◽  
Scanning Electron

In an effort to enhance the reliability of clamp load estimation in bolted joints, this experimental study investigates the effect of tightening speed and coating on both the torque-tension relationship and wear pattern in threaded fastener applications. The fastener torque-tension relationship is highly sensitive to normal variations in the coefficients of friction between threads and between the turning head and the surface of the joint. Hence, the initial level of the joint clamp load and the overall integrity and reliability of a bolted assembly are significantly influenced by the friction coefficients. The effect of repeated tightening and loosening is also investigated using M12, class 8.8 fasteners with and without zinc coating. The torque-tension relationship is examined in terms of the nondimensional nut factor K. The wear pattern is examined by monitoring the changes in surface roughness using a WYKO optical profiler and by using a LECO optical microscope. A Hitachi S-3200N scanning electron microscope is used to examine the contact surfaces under the fastener head after each tightening/loosening cycle. Experimental data on the effect of tightening speed, fastener coating, and repeated tightening are presented and analyzed.

scholarly journals PELAPISAN PERMUKAAN DALAM NOSEL ROKET RKX100 DENGAN Cr2C3-NiCr HVOF: OPTIMASI KEKUATAN LEKAT MELALUI VARIASI KEKASARAN PERMUKAAN

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Bondan T.Sofyan ◽  
Yus Prasetyo ◽  
Sayid Ardiansyah ◽  
Yus Prasetyo ◽  
Edy Sofyan
Keyword(s):  
Surface Roughness ◽  
Thermal Spray ◽  
Bonding Strength ◽  
Spray Coating ◽  
Hardness Measurement ◽  
Thermal Spray Coating ◽  
Optical Microscope ◽  
Mechanical Interlocking ◽  
Micro Hardness ◽  
Scanning Electron

Nozzle of RKX100 rocket contributes 30 percent to the total weight of the structure, so that allowing further research on weight reduction. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. A series of study on the characteristics of various type of HVOF coating material have been being conducted. This paper presented the investigation on the HVOF Cr2C3-NiCr thermal spray coating, in particular, the optimization of bonding strength by varying surface roughness of substrates. Characterization included bonding strength test, micro hardness measurement and micro structural observation with optical microscope and scanning electron micriscope (SEM). The results showed that grit blasting pressure increass the surface roughness from 4,54 um to 5.72 um at the pressure of 6 bar. Average micro hardness of the coating was 631 VHN 300. Coating applied to the surface with rougness of 5.42 um possessed the highest bonding strength, 44 MPa. Microstructural observation by using optical microscope and scanning electron microscope (SEM) confirmed dense lamellae structure with variable composition. High coating adherence was found to be due to mechanical interlocking.

The Evaluation of Tool Wears in Machining of SiCp/Al Composites

2013 ◽  
Vol 764 ◽  
pp. 61-64
Author(s):  
Yang Jun Wang ◽  
Tao Chen ◽  
Ming Qiang Pan ◽  
Ji Zhu Liu ◽  
Li Guo Chen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Flank Wear ◽  
Adhesive Wear ◽  
Cutting Tools ◽  
Optical Microscope ◽  
Coated Tools ◽  
Wear Mode ◽  
Scanning Electron

In this paper an experimental study in milling of SiCp/Al composites on a high precision machine was carried out by using TiN coated tools, TiAlN coated tools and carbide tools. The result of tool wear was observed and measured by an optical microscope and a scanning electron microscope (SEM). The results show that the main wear mode is the flank wear and the wear mechanism is abrasive wear and adhesive wear for the cutting tools used in the experiment.

Comparison of Microscale Rapid Prototyping Techniques for Microfluidic Applications

2014 ◽  
Author(s):  
Gordon D. Hoople ◽  
David A. Rolfe ◽  
Katherine C. McKinstry ◽  
Joanna R. Noble ◽  
David A. Dornfeld ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Laser Ablation ◽  
Rapid Prototyping ◽  
Microfluidic Devices ◽  
Optical Microscope ◽  
Microfluidic Channels ◽  
Recent Developments ◽  
3D Printed ◽  
Small Feature ◽  
Scanning Electron

Recent developments in microfluidics have opened up new interest in rapid prototyping with features on the microscale. Microfluidic devices are traditionally fabricated using photolithography, however this process can be time consuming and challenging. Laser ablation has emerged as the preferred solution for rapid prototyping of these devices. This paper explores the state of rapid prototyping for microfluidic devices by comparing laser ablation to micromilling and 3D printing. A microfluidic sample part was fabricated using these three methods. Accuracy of the features and surface roughness were measured using a surface profilometer, scanning electron microscope, and optical microscope. Micromilling was found to produce the most accurate features and best surface finish down to ∼100 μm, however it did not achieve the small feature sizes produced by laser ablation. 3D printed parts, though easily manufactured, were inadequate for most microfluidics applications. While laser ablation created somewhat rough and erratic channels, the process was within typical dimensions for microfluidic channels and should remain the default for microfluidic rapid prototyping.

Fabrication of Ultra-Fine Abrasive Polishing Pads by Gel Technique

2006 ◽  
Vol 532-533 ◽  
pp. 468-471 ◽  
Author(s):  
Juan Liu ◽  
Yi Qing Yu ◽  
Xi Peng Xu
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Silicon Wafer ◽  
Optical Microscope ◽  
Mirror Surface ◽  
Polishing Pad ◽  
Average Grain Size ◽  
Gel Technique ◽  
Surface Morphologies ◽  
Polishing Pads

In this paper, an experimental study was carried out to fabricate a new kind of ultra-fine abrasive polishing pad by means of gel technology. The polishing pad was then used to polish silicon wafer on a nano-polishing machine. Optical microscope and ZYGO 3D surface analyzer were applied to observe the surface morphologies of the silicon wafer. Meanwhile, surface morphology of ultra-fine abrasive polishing pad was observed by ESEM. No obvious gathering of ultra-fine grains were found on the ultra-fine abrasive pad. The surface roughness (Ra) of the silicon wafer was reduced to 0.3nm after being polished by the abrasives with average grain size of 10μm. Mirror surface can be realized after being polished with the polishing pad.

Examination of Machining Parameters on the Surface Roughness of Stavax ESR Material Using Electro Discharge Machining

2016 ◽  
Vol 1133 ◽  
pp. 339-343
Author(s):  
Mebrahitom Asmelash ◽  
Muhamad Azhari
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Optical Microscope ◽  
Machining Parameters ◽  
Mould Insert ◽  
Machined Surface ◽  
Peak Current ◽  
Electro Discharge Machining ◽  
Spark Gap

An experimental study was conducted to investigate the effect of EDM die sinking machining parameters on surface roughness of Stavax material for mould insert. The spark gap, peak current and servo voltage were manipulated to find the best combination of EDM machining parameters. The surface roughness of the machined surface of each specimen was measured using Perthometer and the image of texture was observed by using optical microscope. It was observed that the surface roughness was highly affected by the spark gap and peak current whereas the servo voltage had little effect.

EXPERIMENTAL STUDY OF THE KINEMATIC PARAMETERS OF MOVEMENT OF CARS FORCED IDLE MOTION

2018 ◽  
pp. 52-57
Author(s):  
Ivelin Kostov
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Experimental Research ◽  
Kinematic Parameters ◽  
Research Results ◽  
Software Product

In the work brought some experimental data of kinematic parameters of movement of cars forced idle, as the software product was used to diagnose 900 ATS, which recorded kinematic parameters of vehicle. On the basis of the conducted experimental research results are shown tabulated and analysed.

Improving of quality of gate assembly contact surfaces of high-pressure fi ttings by diamond burnishing

2020 ◽  
pp. 99-104
Author(s):  
S.A. Zaydes ◽  
A.N. Mashukov ◽  
T.Ya. Druzhinina
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Main Part ◽  
Conical Surface ◽  
The Real ◽  
Metal Seal ◽  
Diamond Burnishing ◽  
Air Tightness ◽  
Contact Surfaces

The contact belt of the gate assembly is the main part of high pressure fittings. The serviceability of the fittings assembly as whole depends on the air-tightness and quality of the mating surfaces. The technology of diamond burnishing allows to increase the interface of the nodes by red ucing the surface roughness of the metal-to-metal seal. The real experience for improving of the fittings contact belt due to the use of diamond burnishing of the nozzles seats and the conical surface of the rods.

Comparative Study of Acid Etching on Dental Enamel

2018 ◽  
Vol 69 (10) ◽  
pp. 2913-2915
Author(s):  
Daniela Jumanca ◽  
Anamaria Matichescu ◽  
Atena Galuscan ◽  
Laura Cristina Rusu ◽  
Cornelia Muntean
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Orthophosphoric Acid ◽  
Dental Enamel ◽  
Acid Etching ◽  
Sealing Material ◽  
Mechanical Bond ◽  
Materials Used ◽  
Scanning Electron

This experimental study aims to analyse the effectiveness of various materials used in demineralisation of dental enamel. This work aims to create a mechanical bond by filling the pegs with sealing material. In order to achieve this goal, five teeth were compared using different concentrations of orthophosphoric acid and exposure times. In this regard, five different tests were performed and the results were analysed using the SEM technique (scanning electron microscopy). These comparative analyses revealed that etching using 35% orthophosphoric acid for one minute and etching using Icon Etch for two minutes were the most effective.

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