ASTM – 75 – Download as PDF File .pdf), Text File .txt) or read online. This standard is issued under the ﬁxed designation D ; the number. ASTM D Standard Test Method for Tensile Strength and Young’s Modulus for High-Modulus Single-Filament Materials. 75th Edition, February 28, Download scientific diagram | Tensile test speciment ASTM D Figure 2. Set up for the fiber tensile test from publication: Application of taguchi method for .
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Surface modification of PBO fiber by electrostatic discharge for composites. In this paper, the effects of surface treatment on the modification of PBO fiber and its composite materials have been investigated wstm electrostatic discharge under atmospheric pressure.
No chemical discharge was involved. The fiber surface morphology was examined by scanning electron microscopy.
The corresponding change in fiber tensile strength was measured by MTS tensile testing machine using a cardboard sample frame.
The surface free energy was quantified using a dynamic contact angle analysis system. In addition, the interfacial adhesion properties of the PBO fiber reinforced epoxy composites were studied by microbond pull-out tests.
In addition, the composite failure mode would be aastm. The PBO fiber samples were cleaned and dried before being used in the electrostatic discharge treatment study. Two different operating voltages were studied at room temperature and atmospheric pressure: Much higher voltage would create unstable discharge that resulted sparks and could damage the fiber samples. The distance between the discharge electrode and the samples was about 1.
The surface morphology of PBO fiber both before and after the electrostatic discharge treatment was examined by scanning electron microscopy.
The corresponding tensile strength properties of the fiber samples were analyzed by MTS tensile testing machine at room temperature. Each monofilament sample was mounted across a cardboard sample frame using a room temperature curing adhesive according to ASTM D The tensile strength was then d379-75 from the ultimate load divided by the cross-sectional area. The surface free energy of PBO fiber was analyzed from the measured contact angles between each sample and five different liquid contact d379-75, including n-hexadecane, dimethyl sulfoxide DMSOd3379-57 glycol EGformamide and water.
The effects of electrostatic discharge modification on the interfacial adhesion properties between PBO fiber and epoxy matrix were studied by microbond pull-out tests. The Epon type epoxy was premixed with a hardener and delivered to PBO fiber using a syringe.
The cured epoxy was then debonded in shear from PBO fiber by the jaws of a microvice. The microbond specimens were pulled by MTS tensile testing machine at room asym at a crosshead speed of 0. Here, F is the pull-out load, D is the diameter of the fiber, and L is the embedded length. In addition, some unidirectional PBO fiber reinforced epoxy model composites were prepared from fiber strands. These samples were fractured to reveal the interfacial adhesion bonding quality asfm the examination using scanning electron microscopy.
The surface morphology of the treated PBO fibers has been examined by scanning electron microscopy and is shown in Figures 1.
The surface displayed some scars from the electrostatic treatment effects also discharge treatment. It seemed that a thin layer of oxidized substance has been deposited on the surface.
The surface appeared to be still uniform. The degree of surface modification increased with the applied discharge voltage. However, when the applied discharge voltage was above 20 kV, the treatment process could have seriously damaged the fiber structure integrity.