All issues
Volume 19 (1993)
- Issue 6 Pages 201-
- Issue 5 Pages 163-
- Issue 4 Pages 125-
- Issue 3 Pages 81-
- Issue 2 Pages 39-
- Issue 1 Pages 1-
Volume 19, Issue 2
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
-
Tatsundo KITAMURA1993 Volume 19 Issue 2 Pages 39-45
Published: March 15, 1993
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSDownload PDF (4389K) -
I. CHOU, I. KIMPARA, K. KAGEYAMA, I. OHSAWA1993 Volume 19 Issue 2 Pages 46-54
Published: March 15, 1993
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSThe objective of this study was to investigate the effect of moisture absorption on the Mode I and the Mode II interlaminar fracture toughness of CFRP laminates. DCB (Double Cantilever Beam) test and ENF (End Notched Flexure) test were conducted on unidirectional CF/EPOXY specimens. Three moisture absorbing conditions were employed in this study. They were dry condition, 0.2 wt% absorbed condition and 1.6 wt% absorbed condition. In both fracture modes, Go, the interlaminar fracture toughness at the onset of nonlinear response, was the highest in case of 0.2 wt% absorbed specimens and the lowest in case of 1.6 wt% absorbed specimens. However, the interlaminar fracture toughness at the maximum load point, in both fracture modes, had no effects of moisture absorption. Through the fracture surface observation by SEM, it was pointed out that the moisture absorption in large quantities made the fiber/matrix interfacial strength poorer and this fact related with the lowest Go values in both fracture modes.View full abstractDownload PDF (5674K) -
Characteristics of AE Sensors and Threshold on Acoustic Emission MeasurementH. MORINAKA, T. FUJII1993 Volume 19 Issue 2 Pages 55-63
Published: March 15, 1993
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSThis paper presents how the frequency characteristics of AE sensors and threshold affect acoustic emission measurement. Static and fatigue tests of FRP reinforced by plain woven glass fabric were conducted. Three different types of AE sensors having different sensitivities with respect to frequency were used simultaneously to distinguish the difference of observed AE data. Following results are obtained from the test. 1. Threshold of AE system strongly affects observed AE data. Namely, observed AE under a certain threshold condition is different from that under another condition. This threshold dependence is due to the dead time and resolution time of AE measuring system. Total AE events and rate do not always increase as the threshold becomes lower. AE observation at a different threshold condition might derive different conclusions. 2. The frequency characteristics of AE sensors strongly affect the observed AE data as well as the threshold under a static loading while a rough tendency of total AE count record agrees with each other under a fatigue loading. The above results attract a strong attention that AE sensors must be carefully selected according to material AE nature taking the machine characteristics (i.e., dead time and so on) into consideration. It is quite difficult to compare the AE data obtained at a certain condition with the data obtained using different AE sensors or different condition.View full abstractDownload PDF (2644K) -
X. YAN, T. OHSAWA, T. OZAKI1993 Volume 19 Issue 2 Pages 64-71
Published: March 15, 1993
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSThe paper presents laser holography and photoelastic image methods for studying local stress conditions inside materials especially composite materials. A new experimental method was presented to obtain isochromatics (σ1-σ2) in photoelasticity and isopachics (σ1+σ2) in holographic interferometry, which allows easy separation of principal stress σ1, σ2. The proposed method was applied to quantitative evaluation both in epoxy materials and in glass fiber-reinforced epoxy composites. The effect of a single fiber on the principal stress distribution in the epoxy was studied.View full abstractDownload PDF (6628K) -
Effect of Reinforcement Fiber on Fracture MechanismH. KAWADA, Y. YAMAMOTO, T. YOSHIDA, I. OHTA, I. HAYASHI1993 Volume 19 Issue 2 Pages 72-78
Published: March 15, 1993
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSObjective of this paper is to reveal characteristics of bending fracture in C/C composites with two types of the reinforcement (T300 produced by Toray and HTA by Toho Rayon, both PAN based high-strength type carbon fiber). Satin weave carbon fabric/carbon matrix laminates were fabricated, for which CFRP laminates were prepared with the hot press molding and then carbonized at about 1000°C.Both fibers have nearly the same mechanical properties. First of all, change of laminates thickness was investigated before and after the carbonization process. Three-point bending tests were carried out using the specimens with various span/thickness ratios. Fracture surfaces and crack-propagation behaviors were characterized with a SEM.View full abstractDownload PDF (4722K) -
[in Japanese]1993 Volume 19 Issue 2 Pages 80
Published: March 15, 1993
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSDownload PDF (141K)
- |<
- <
- 1
- >
- >|