Proportional limit of wood obtained from a load-time diagram during an impact bending test

2002 ◽  
Vol 48 (6) ◽  
pp. 527-531
Author(s):  
Yoshitaka Kubojima ◽  
Hideo Kato ◽  
Mario Tonosaki
Author(s):  
Tomáš Binar ◽  
Jiří Švarc ◽  
Petr Dostál ◽  
Michal Šustr ◽  
Jan Tippner

This article deals with the spread of corrosion in material at different exposure times, and its effect on the measured brittle fracture and notch impact strength under different temperature conditions. To assess the degradational effect of corrosion on the material characteristics represented by the measured impact strength, we conducted a fractographic analysis of fracture surfaces, the aim of which was to evaluate the spread of corrosion in the material. In the first part of the experiment, two corrosion tests are simulated with a duration time of 432 and 648 hours, to compare the degradation effect of corrosion on the notch impact strength, depending on the duration of the corrosion tests. The following part shows the results of the impact bending test, where the experiment was conducted in an area of reduced and increased temperatures. The final part summarizes the results of the fractographic analysis of sample fracture surfaces from the impact bending tests. Based on the measured the length of the corrosion cracks, we analyzed the sample at the notch and from the material surface after the impact bending test.


2004 ◽  
Vol 2004.1 (0) ◽  
pp. 195-196
Author(s):  
Akihiro HOJO ◽  
Akiyosi CHATANI ◽  
Hiroshi TACHIYA

2002 ◽  
Vol 124 (4) ◽  
pp. 374-378 ◽  
Author(s):  
C. M. Lawrence Wu ◽  
Robert K. Y. Li ◽  
N. H. Yeung

Isotropic conductive adhesives (ICA) have been considered as replacement materials for lead-tin solder alloys. In this paper, the post-impact shear strength of ICA surface mount (SM) joints was obtained experimentally and compared with that of SM lead-tin joints. The dynamic impact energy was provided in the form of three-point bending on the PCB using equipment called the split Hopkinson bar. Strain rates of over 4000/s were used for the impact bending test. The action of impact bending was used to simulate the effect on the PCB and the interconnection as a result of high energy impact on an electronic equipment. Shear test was then performed to examine the change in strength of the ICA joints as a result of impact damage. It was found that the SM ICA joints failed due to impact at a strain rate just over 4000/s. Microstructural examination carried out using a scanning electron microscope revealed that the interface between the ICA and copper pad on the PCB was the weakest region of the joint.


1957 ◽  
Vol 6 (42) ◽  
pp. 168-171
Author(s):  
Taketo YOKOYAMA ◽  
Fumio HASHIMOTO
Keyword(s):  

2020 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Huijun Dong ◽  
Mina Raiesi ◽  
Mohsen Bahmani ◽  
Ali Jafari ◽  
Hamed Aghajani

Urban trees are one of the valuable storage in metropolitan areas. Nowadays, a particular attention is paid to the trees and spends million dollars per year to their maintenance. Trees are often subjected to abiotic factors, such as fungi, bacteria, and insects, which lead to decline mechanical strength and wood properties. The objective of this study was to determine the potential degradation of Elm tree wood by Phellinus pomaceus fungi, and Biscogniauxia mediteranae endophyte. Biological decay tests were done according to EN 113 standard and impact bending test in accordance with ASTM-D256-04 standard. The results indicated that with longer incubation time, weight loss increased for both sapwood and heartwood. Fungal deterioration leads to changes in the impact bending. In order to manage street trees, knowing tree characteristics is very important and should be regularly monitored and evaluated in order to identify defects in the trees.


1977 ◽  
Vol 43 (1) ◽  
pp. 203-217 ◽  
Author(s):  
K. Kussmaul ◽  
E. Krägeloh ◽  
A. Kochendörfer ◽  
E. Hagedorn

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