Vibration Test of Titanium Alloy Pipes

2012 ◽  
Vol 184-185 ◽  
pp. 701-706
Author(s):  
Ming Xing Qiu ◽  
Chuang Shao ◽  
Yong Zhou ◽  
Li Hua Yue

In order to determine the fatigue limits of two kinds of titanium alloy pipes connected by welding and rolling, fatigue tests were carried out by the Aero-Criterion which gives vibration fatigue test method and failure criteria. A laser-displacement-sensor was used at the free end and a strain-gauge at the root of the pipe specimen. The test result shows that the fatigue limit of the welded pipe is higher than the rolled one. In the end some new findings are listed according to the test.

2012 ◽  
Vol 248 ◽  
pp. 74-78
Author(s):  
Chuang Shao ◽  
Ming Xing Qiu ◽  
Yi Xuan Li

In order to determine the fatigue limits of two kinds of titanium alloy joint pipes connected by welding and rolling, the fatigue tests were carried out by test standard which defines the test method and failure rule. One cantilever-beam specimen was fixed on the shaker by the special fixture. The laser-displacement-sensor was fixed at the free end of pipe and the strain-gauge was adhesive at the root of the pipe. The first frequency of specimen was measured by these sensors. The first resonance frequency fell rapidly with the increment of the excitation loads of the shaker. The failure rule (1% drop of resonance frequency) of the standard was not same with the fatigue limit test of these connected pipes at the test beginning. In order to define the lives of two kinds of pipes, the stair method of sweep test was used to eliminate the effect of connection gap. Then the vibration fatigue of every specimen was tested at the last resonance frequency. And all the fatigue tests were finished using the failure rule which defines 1% drop of the steady resonance frequency.


Author(s):  
Eric B. Halfmann ◽  
C. Steve Suh ◽  
N. P. Hung

The workpiece and tool vibrations in a lathe are experimentally studied to establish improved understanding of cutting dynamics that would support efforts in exceeding the current limits of the turning process. A Keyence laser displacement sensor is employed to monitor the workpiece and tool vibrations during chatter-free and chatter cutting. A procedure is developed that utilizes instantaneous frequency (IF) to identify the modes related to measurement noise and those innate of the cutting process. Instantaneous frequency is shown to thoroughly characterize the underlying turning dynamics and identify the exact moment in time when chatter fully developed. That IF provides the needed resolution for identifying the onset of chatter suggests that the stability of the process should be monitored in the time-frequency domain to effectively detect and characterize machining instability. It is determined that for the cutting tests performed chatters of the workpiece and tool are associated with the changing of the spectral components and more specifically period-doubling bifurcation. The analysis presented provides a view of the underlying dynamics of the lathe process which has not been experimentally observed before.


2021 ◽  
pp. 109963622110204
Author(s):  
Zhi-Wei Wang ◽  
Yang-Zhou Lai ◽  
Li-Jun Wang

The bending fatigue tests of single-wall and double-wall corrugated paperboards were conducted to obtain the εrms– N curves under sinusoidal and random loads in this paper. The εrms– N equation of corrugated paperboard can be described by modified Coffin–Manson model considering the effect of mean stress. Four independent fatigue parameters are obtained for single-wall and double-wall corrugated paperboards. The εrms– N curve under random load moves left and rotates clockwise compared with that under sinusoidal load. The fatigue life under random load is much less than that under sinusoidal load, and the fatigue design of corrugated box should be based on the fatigue result under random load. The stiffness degradation and energy dissipation of double-wall corrugated paperboard before approaching fatigue failure are very different from that of single-wall one. For double-wall corrugated paperboard, two turning points occur in the stiffness degradation, and fluctuation occurs in the energy dissipation. Different from metal materials, the bending fatigue failure of corrugated paperboard is a process of wrinkle forming, spreading, and folding. The results obtained have practical values for the design of vibration fatigue of corrugated box.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Jiang ◽  
Gun Jin Yun ◽  
Li Zhao ◽  
Junyong Tao

Novel accelerated random vibration fatigue test methodology and strategy are proposed, which can generate a design of the experimental test plan significantly reducing the test time and the sample size. Based on theoretical analysis and fatigue damage model, several groups of random vibration fatigue tests were designed and conducted with the aim of investigating effects of both Gaussian and non-Gaussian random excitation on the vibration fatigue. First, stress responses at a weak point of a notched specimen structure were measured under different base random excitations. According to the measured stress responses, the structural fatigue lives corresponding to the different vibrational excitations were predicted by using the WAFO simulation technique. Second, a couple of destructive vibration fatigue tests were carried out to validate the accuracy of the WAFO fatigue life prediction method. After applying the proposed experimental and numerical simulation methods, various factors that affect the vibration fatigue life of structures were systematically studied, including root mean squares of acceleration, power spectral density, power spectral bandwidth, and kurtosis. The feasibility of WAFO for non-Gaussian vibration fatigue life prediction and the use of non-Gaussian vibration excitation for accelerated fatigue testing were experimentally verified.


2013 ◽  
Vol 677 ◽  
pp. 384-387 ◽  
Author(s):  
Wai Kei Ricky Kot ◽  
Luen Chow Chan

In this paper, a visualisation system will be discussed that can be used to capture the deformation profile of the sheet blank during sheet metal forming processes, such as deep drawing and shape forming. The visualisation system utilizes a 2D laser displacement sensor for deformation profile acquisition. The sensor is embedded in the die and the laser propagates through the die to detect the profile change of the specimen concealed in the die during operation. The captured profile data will be collected, manipulated and transferred to a monitor for display via a controller. This visualisation of the deformation profile will provide engineers and researchers with an intuitive means of analysing and diagnosing the deformation process during sheet metal forming.


1999 ◽  
Author(s):  
Masatake Shiraishi ◽  
Gongjun Yang

Abstract A laser displacement sensor which has a resolution of 0.5 μm was used to determine the measurement of a curved workpiece profile in turning. This sensor is attached to a specially designed stage and is operated by three motors which are controlled by a fuzzy control algorithm. The experimental results show that the measuring system can be applied to workpieces having inclination angles of up to around 45°. The proposed measuring system has a practical measuring accuracy to within ten micrometers.


2013 ◽  
Vol 328 ◽  
pp. 193-197
Author(s):  
Si Jin Xin ◽  
Zhen Tong

The metal fatigue is an important factor to cause an accident in machine operation, so metal fatigue test is a significant procedure in manufacturing. Fiber Bragg Grating (FBG), as an innovative sensor, has been applied to the measurement of various rotating machines. In this paper, the time-frequency analysis is used to detect the fatigue feature of a titanium alloy measured by FBG sensors. Furthermore, the Hilbert-Huang transform (HHT) is more effective to observe the fatigue limit of the titanium alloy sheet, compared to the Wavelet transform (WT).


Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 271
Author(s):  
Bo Wen ◽  
Sho Sekine ◽  
Shinichi Osawa ◽  
Yuki Shimizu ◽  
Hiraku Matsukuma ◽  
...  

This paper describes a comparison of the mechanical structures (a double-sided beam and a cantilever beam) of a probe in a tool edge profiler for the measurement of a micro-cutting tool. The tool edge profiler consists of a positioning unit having a pair of one-axis DC servo motor stages and a probe unit having a laser displacement sensor and a probe composed of a stylus and a mechanical beam; on-machine measurement of a tool cutting edge can be conducted with a low contact force through measuring the deformation of the probe by the laser displacement sensor while monitoring the tool position. Meanwhile, the mechanical structure of the probe could affect the performance of measurement of the edge profile of a precision cutting tool. In this paper, the measurement principle of the tool edge profile is firstly introduced; after that, slopes and a top-flat of a cutting tool sample are measured by using a cantilever-type probe and a double-sided beam-type probe, respectively. The measurement performances of the two probes are compared through experiments and theoretical measurement uncertainty analysis.


2021 ◽  
Vol 7 (1) ◽  
pp. 101-120
Author(s):  
M. Chotibuddin

Learning and teaching are the most important activities in the whole educational process. This implies that the success or failure of the educational goals depends on how to design the teaching and learning process (learning) professionally. The success of the learning process cannot be separated from the preparation of students and the preparation of educators. In learning activities, methods are needed for educators and their use varies according to the goals to be achieved after teaching ends. An educator will not be able to carry out his duties if he does not master any of the teaching methods that have been formulated. The methods used in data collection are the observation method and the test method. The data analysis used was the instrument validity test, the normality test and the homogeneity test. The results of the research carried out proved that student learning outcomes before and after using the jigsaw method could be seen from the average pre-test scores of 62.00 and 76.60 post-test results. The pre-test result value is lower than the post-test score, so it means that there are differences in student learning outcomes before and after using the jigsaw method in the learning process.The percentage of the completeness criteria of the pre-test result value is 28%, while the posttest result score is 68%. From this data, it can be seen that using the jigsaw method can affect student learning outcomes. Hypothesis testing using the Product Moment Correlation test and Paired Sample T-test with the help of SPSS 20 software in the sig (2-tailed) section is known to be 0.000 <0.05. As the basis for decision making in the Product Moment Correlation test anddecision guidelines based on the probability value, it can be concluded that H0 is rejected and Ha is accepted. This means that the jigsaw method can affect the improvement of learning outcomes of class V Islamic Religious Education at MI Muhammadiyah 09 Kranji Lamongan


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