Prevention of Delamination during Drilling of Composite Material Using Vibration

2004 ◽  
Vol 261-263 ◽  
pp. 381-386 ◽  
Author(s):  
Shigeru Aoki ◽  
Toshiyasu Nishimura

Prevention method of delamination at adhesive layer during drilling of composite material using vibration is examined. First, this method is examined experimentally. As vibrational load, relatively low frequency vibration and ultrasonic vibration are used. It is concluded occurrence of delamination is less when vibration is used during drilling. Next, experimental results are examined by analytical method. Adhesive layer is assumed to be damping component. Condition of occurrence of delamination is proposed.

2005 ◽  
Vol 291-292 ◽  
pp. 465-470 ◽  
Author(s):  
Shigeru Aoki ◽  
Seiji Hirai ◽  
Tadashi Nishimura

Composite materials are used for many structures because of its high strong-to-weight ratio and easy formation. Secondary machining processes such as drilling and sawing are required to assemble and join composite materials to other structures. When composite materials are machined, delamination occurs at adhesive layer between laminated layers. It is well known that it is possible to cut hard metals and to improve precision of machined surface by using ultrasonic vibration. This method is applied to machining composite materials in this paper. Drilling of composite materials is focused on. First, this method is examined experimentally. Next, experimental results are examined by analytical method. Using condition of experiment, prevention of delamination can be demonstrated from the proposed analytical method.


2013 ◽  
Vol 416-417 ◽  
pp. 860-865
Author(s):  
Wu Sung Yao ◽  
Po Wen Hsueh ◽  
Mi Ching Tsai

This paper investigates an active anti-vibration system, and the isolation of low-frequency vibration is studied. A model reference control of the anti-vibration system with a sky-hook damper and impedance control is analyzed. An illustrated example of a single-degree-of-freedom anti-vibration system driven by a tubular linear servomotor is given to verify the performance of the proposed control design. Experimental results are given to show that the peak resonance value of 0dB within a frequency of 10Hz can be achieved successively.


2013 ◽  
Vol 797 ◽  
pp. 450-454 ◽  
Author(s):  
Wei Min Lin ◽  
Sze Keat Chee ◽  
Hirofumi Suzuki ◽  
Toshiro Higuchi

Demands of precision molds with complicated microstructures for digital devices such as DVD pick-up system, and medical devices such as μ-TAS and solar optics etc. are increasing. To enhance precision, the structured molds must be polished after grinding or cutting in order to improve the surface roughness. In this paper, a two-dimensional low frequency vibration (LFV) polishing actuator using PZT is proposed and developed. The LFV consists of four mechanical amplitude magnified actuators, a multilayer stacked piezoelectric actuator (PZT) incorporated with mechanical transformer, and a center piece. In the polishing experiments, HIPM workpieces were polished with WA slurry by the rotation & revolution type polishing method (RRP). The surface roughness of the work pieces and material removal amount (polished amount) was also evaluated. From the experimental results, it was found that the application of low frequency vibration is useful for realizing higher precision in the polishing of micro structured molds.


Author(s):  
Matthew Trapuzzano ◽  
Nathan Crane ◽  
Rasim Guldiken ◽  
Andrés Tejada-Martínez

Abstract Adhesives, medical devices, and many cleaning products depend on the wetting of liquids on solid surfaces. The liquid/solid interaction depends on chemistry, surface topology, and external energy input. For instance, surfactants are commonly used in cleaning solutions to improve their effectiveness, and electrical fields are frequently used to control the contact angle of liquid droplets. Low frequency vibration has been used to spread, move, and manipulate droplets using the mode shape oscillations of the droplet to displace the contact line. Ultrasonic vibration (above 20 kHz) can also cause a liquid droplet to wet or spread out on a solid surface under the right circumstances. We have previously demonstrated that ultrasonic vibration can be used to control the wetting/spreading of liquid droplets on smooth hydrophobic surfaces and that the response is relatively insensitive to excitation frequency or fluid properties [1]. This paper reports on the use of ultrasonic vibration to initiate spreading on surfaces with etched pillars. Ultrasonic vibration successfully initiated a transition from Cassie to Wenzel states in all geometries with no apparent need to tune excitation frequencies to the geometry. However, the magnitude of the acceleration required to initiate the transition decreased with increased pillar spacing. For small pillar spacing, some smooth spreading in the Cassie wetting mode was observed before transition.


Author(s):  
K. Hama

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.


2020 ◽  
Vol 2020 (14) ◽  
pp. 305-1-305-6
Author(s):  
Tianyu Li ◽  
Camilo G. Aguilar ◽  
Ronald F. Agyei ◽  
Imad A. Hanhan ◽  
Michael D. Sangid ◽  
...  

In this paper, we extend our previous 2D connected-tube marked point process (MPP) model to a 3D connected-tube MPP model for fiber detection. In the 3D case, a tube is represented by a cylinder model with two spherical areas at its ends. The spherical area is used to define connection priors that encourage connection of tubes that belong to the same fiber. Since each long fiber can be fitted by a series of connected short tubes, the proposed model is capable of detecting curved long tubes. We present experimental results on fiber-reinforced composite material images to show the performance of our method.


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