Study on Mechanism of Tap Breakage in Low Frequency Torsional Vibration Tapping

2010 ◽  
Vol 37-38 ◽  
pp. 1306-1310
Author(s):  
Feng Qi Han ◽  
Zhi Zun Li ◽  
De Yuan Zhang
Keyword(s):  
Stress State ◽  
Service Life ◽  
Tensile Stress ◽  
Failure Mode ◽  
Torsional Vibration ◽  
Impact Load ◽  
Low Frequency ◽  
Rake Angle ◽  
Shock Resistance ◽  
Large Tensile Stress

Early breakage of tap often occurs when tapping on difficult-to-cut materials with the method of low frequency torsional vibration tapping, which decreases the technological effect and restricts its application. The effect of impact load on tap breakage in vibration tapping was analyzed, and the stress state in tap teeth was simulated by FEM, on this basis, it is concluded that too large tensile stress in tap teeth is the main cause of early breakage of tap. To reduce the tensile stress and enhance the shock resistance of tap teeth, the tap should be ground to minor negative rake angle. Experiments showed that the failure mode of grinded taps changed to wear, and thereby the service life of tap was prolonged significantly.

scholarly journals Study on Vibration Tapping for SiCp/Al Particle-reinforced Metal Matrix Composite

2018 ◽  
Vol 228 ◽  
pp. 04005
Author(s):  
Yang Liu ◽  
Jing Zhao
Keyword(s):  
Service Life ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Torsional Vibration ◽  
Metal Matrix ◽  
Low Frequency ◽  
Cutting Fluid

Aiming at answering the question that low tap service life of ordinary tapping and bad thread quality on particle-reinforced metal matrix composite SiCp/Al, the reason of question and the mechanism of low-frequency torsional vibration tapping are analyzed. The experiments were carried out to compare the tap service life and the thread quality of vibration tapping with ordinary tapping without cutting fluid. It indicates that vibration tapping could make tapping torque reduce greatly, the tap service life could be prolonged twice comparing with continuous tapping without cutting fluid, and could ensure the good thread quality. Moreover, it promotes metal matrix composite’s further application.

Study on Step Type Vibration Tapping of Superalloy

2014 ◽  
Vol 496-500 ◽  
pp. 401-405
Author(s):  
Feng Qi Han ◽  
Zhi Zun Li ◽  
De Yuan Zhang
Keyword(s):  
Experimental Data ◽  
Service Life ◽  
Torsional Vibration ◽  
Low Frequency ◽  
Spindle Speed ◽  
Cutting Angle ◽  
Step Type

Service life of tap is shorter when low frequency torsional vibration tapping is used to tap on superalloy GH4169. The analysis of experimental data show that excessive repeated cutting times and high friction speed result in rapid wear of tap. In order to avoid above unfavorable factors, step type vibration tapping is proposed, which has larger cutting angle, such as 90°, and lower spindle speed. It was proved by experiments on superalloy GH4169 that service life of tap of step type vibration tapping is about twice of that of common low frequency torsional vibration tapping .

scholarly journals Experimental and Numerical Simulation to Study the Reduction of Welding Residual Stress by Ultrasonic Impact Treatment

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 837
Author(s):  
Jianfei Chen ◽  
Jingyu Chu ◽  
Wenchun Jiang ◽  
Bin Yao ◽  
Fan Zhou ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Tensile Stress ◽  
Residual Stresses ◽  
Thick Plate ◽  
Welding Residual Stress ◽  
Diffraction Measurement ◽  
Ultrasonic Impact Treatment ◽  
Longitudinal Residual Stress ◽  
Large Tensile Stress

In this study, the effects of ultrasonic impact treatment (UIT) on the residual stress in a repair welding joint are investigated by experimental and finite element methods. A three-dimensional numerical analysis approach including a thermomechanical-coupled welding simulation and dynamic elastic-plastic UIT simulation is developed, which has been validated by X-ray diffraction measurement and indentation strain method. The results show that longitudinal residual stresses basically turned into the small tensile stress state from the large tensile stress state, and transverse residual stresses have mainly turned into compressive stresses from large tensile stress after the UIT. In the thickness direction, the average decrease of longitudinal residual stress is 259.9 MPa, which is larger than the 149.1 MPa of transverse residual stress. The calculated residual stress distribution after the UIT of the thin plate is compared with that of the thick plate in the literature, with the results showing the stress accumulation layer inside the thick plate. The simulation results show that the elastic strains are decreased slightly and the equivalent plastic strain is increased markedly after UIT, which explains the mechanism of residual stress relaxation.

scholarly journals Design and implementation of a jellyfish otolith-inspired MEMS vector hydrophone for low-frequency detection

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Renxin Wang ◽  
Wei Shen ◽  
Wenjun Zhang ◽  
Jinlong Song ◽  
Nansong Li ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Low Frequency ◽  
Directivity Pattern ◽  
Stress Distributions ◽  
Strong Response ◽  
Underwater Acoustic ◽  
Frequency Detection ◽  
Vector Hydrophone ◽  
Shock Resistance ◽  
Marine Applications

AbstractDetecting low-frequency underwater acoustic signals can be a challenge for marine applications. Inspired by the notably strong response of the auditory organs of pectis jellyfish to ultralow frequencies, a kind of otolith-inspired vector hydrophone (OVH) is developed, enabled by hollow buoyant spheres atop cilia. Full parametric analysis is performed to optimize the cilium structure in order to balance the resonance frequency and sensitivity. After the structural parameters of the OVH are determined, the stress distributions of various vector hydrophones are simulated and analyzed. The shock resistance of the OVH is also investigated. Finally, the OVH is fabricated and calibrated. The receiving sensitivity of the OVH is measured to be as high as −202.1 dB@100 Hz (0 dB@1 V/μPa), and the average equivalent pressure sensitivity over the frequency range of interest of the OVH reaches −173.8 dB when the frequency ranges from 20 to 200 Hz. The 3 dB polar width of the directivity pattern for the OVH is measured as 87°. Moreover, the OVH is demonstrated to operate under 10 MPa hydrostatic pressure. These results show that the OVH is promising in low-frequency underwater acoustic detection.

Determination of the Biaxial Anisotropy Coefficient Using a Single Layer Sheet Metal Compression Test

2021 ◽  
Vol 883 ◽  
pp. 303-308
Author(s):  
Peter Hetz ◽  
Matthias Lenzen ◽  
Martin Kraus ◽  
Marion Merklein
Keyword(s):  
Stress State ◽  
Tensile Stress ◽  
Sheet Metal ◽  
Compression Test ◽  
Test Procedure ◽  
Rolling Direction ◽  
Single Layer ◽  
Material Behavior ◽  
Biaxial Tensile ◽  
Biaxial Tensile Stress

Numerical process design leads to cost and time savings in sheet metal forming processes. Therefore, a modeling of the material behavior is required to map the flow properties of sheet metal. For the identification of current yield criteria, the yield strength and the hardening behavior as well as the Lankford coefficients are taken into account. By considering the anisotropy as a function of rolling direction and stress state, the prediction quality of anisotropic materials is improved by a more accurate modeling of the yield locus curve. According to the current state of the art, the layer compression test is used to determine the corresponding Lankford coefficient for the biaxial tensile stress state. However, the test setup and the test procedure is quite challenging compared to other tests for the material characterization. Due to this, the test is only of limited suitability if only the Lankford coefficient has to be determined. In this contribution, a simplified test is presented. It is a reduction of the layer compression test to one single sheet layer. So the Lankford coefficient for the biaxial tensile stress state can be analyzed with a significantly lower test effort. The results prove the applicability of the proposed test for an easy and time efficient characterization of the biaxial Lankford coefficient.

scholarly journals Failure analysis of the rubber track of a tracked transporter

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878952 ◽  
Author(s):  
Weiwei Liu ◽  
Kai Cheng ◽  
Jun Wang
Keyword(s):  
Stress State ◽  
Tensile Stress ◽  
Failure Analysis ◽  
Test Site ◽  
Strength Theory ◽  
Cycle Index ◽  
Soil Stress ◽  
Machinery Building ◽  
Simple Stress ◽  
Working Hour

Rubber-tracked transporters are becoming increasingly popular in agriculture, forestry and military transportation. Rubber track systems are typically fitted instead of using tyres on the transporter to decrease soil stress and increase trafficability. Therefore, the accurate failure analysis of a rubber track is important. A model for predicting stress distribution along a rubber track is presented in this study. In the model, the stress along a rubber track consists of the vertical stress below the rubber track, tensile stress, bending stress and centrifugal tensile stress. Moreover, fourth strength theory was used to change a complicated stress state to a simple stress state. An experiment was performed at the test site of Harbin First Machinery Building Group Ltd, with a total weight of 61.789 kN. The experiment was conducted to verify and approve the theoretical model. The Miner rule was used to predict the cycle index and working hour of the rubber track, thereby providing a method for predicting the fatigue life of a rubber track.

Low-frequency acoustoelastic-based stress state characterization: Theory and experimental validation

2018 ◽  
Vol 112 ◽  
pp. 417-429 ◽  
Author(s):  
Mohammad I. Albakri ◽  
V.V.N. Sriram Malladi ◽  
Pablo A. Tarazaga
Keyword(s):  
Stress State ◽  
Experimental Validation ◽  
Low Frequency

scholarly journals Enhancing Wear Resistance and Cutting Performance of a Long-Life Micro-Groove Tool in Turning AISI 201

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1515
Author(s):  
Jinxing Wu ◽  
Lin He ◽  
Yanying Wu ◽  
Chaobiao Zhou ◽  
Zhongfei Zou ◽  
...  
Keyword(s):  
Temperature Field ◽  
Service Life ◽  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Rake Angle ◽  
Rake Face ◽  
Crater Wear ◽  
Wear Area

Tool-chip friction increases cutting temperature, aggravates tool wear, and shortens the service life of cutting tools. A micro-groove design of the rake face can improve the wear performance of the tool. In this study, we used the finite element simulation “Deform” to obtain the temperature field distribution of the tool rake face. The size of the micro-groove was determined by selecting a suitable temperature field combined with the characteristics of tool–chip flow in the cutting process, and the tool was prepared using powder metallurgy. The three-direction cutting forces and tool tip temperature were obtained by a cutting test. Compared with the original turning tool, the cutting force and cutting temperature of the micro-groove tool were reduced by more than 20%, the friction coefficient was reduced by more than 14%, the sliding energy was reduced and the shear energy was greatly decreased. According to the analysis of tool wear by SEM (scanning electron microscope) and EDS (energy dispersive X-ray spectroscopy), the crater wear, adhesive wear and oxidation wear of the micro-groove tool were lower than those of the original turning tool. In particular, the change in the crater wear area on the rake face of the original tool and the micro-groove tool was consistent with the cutting temperature and the wear width of the flank face. On the whole, the crater wear area and the change rate of the crater wear area of the micro-groove tool were smaller. Due to the proper microgroove structure of the rake face, the tool-chip contact area decreased, and the second rake angle of the tool became larger. Hence, the tool-chip friction, cutting forces, cutting energy consumption were reduced, tool wear was improved, and the service life of the micro-groove tool was five times longer than that of the original tool.

Sign in / Sign up

Export Citation Format

Share Document