On the Accuracy of Measurement and Calibration of Load Signal in the Instrumented Charpy Impact Test

This research paper deals with an investigation of the influence of honeycomb core compression on the mechanical properties of sandwich structures. These structures consist of prepreg facing layers and two different material types of honeycomb and are produced by modified compression molding called Crush-Core technology. Produced structures are mechanically tested in three-point bending test and subjected to low-velocity impact and Charpy impact test.

Download Full-text

Investigation on Flexural Behavior of Geopolymer-Based Carbon Textile/Basalt Fiber Hybrid Composite

Polymers ◽

10.3390/polym13050751 ◽

2021 ◽

Vol 13 (5) ◽

pp. 751

Author(s):

Chi Hiep Le ◽

Petr Louda ◽

Katarzyna Ewa Buczkowska ◽

Iva Dufkova

Keyword(s):

Flexural Strength ◽

Hybrid Composite ◽

Impact Test ◽

Basalt Fiber ◽

Charpy Impact ◽

Charpy Impact Test ◽

Flexural Behavior ◽

Thin Plates ◽

The One ◽

Dose Levels

This paper presents an experimental research on the mechanical properties of the hybrid composite thin-plates of the short basalt fibers (CBFs)/carbon textile-reinforced geomortar. The effect of fiber contents and lengths of CBFs on the flexural behavior of carbon textile-reinforced geopolymer specimens (TRGs) was investigated by the four-point flexural strength and Charpy impact test. The experimental results of hybrid TRGs, on the one hand, were compared with reference TRGs, without CBF addition; on the other hand, they were compared with the results of our previous publication. According to the mixing manner applied, fresh geomortar indicated a marked reduction in workability, increasing the CBF loading. Furthermore, using CBFs with lengths of 12 mm and 24 mm makes it easy to form the fiber clusters in geomortar during mixing. According to all the CBF loadings used, it was found that TRGs showed a significant improvement in both static and dynamic flexural strength. However, the failure mode of these TRGs is similar to that of the reference TRGs, described by the process of fiber debonding or simultaneously fiber debonding and collapse. In comparison with our prior work results, neither the CBF dose levels nor the fiber lengths used in this work have yielded a positive effect on the failure manner of TRGs. According to the results of the Charpy impact test, this reveals that the anchoring capacity of textile layers in geomortar plays an important role in specimens’ strength.

Download Full-text

Effect of main layer thickness on the response of multi layer bonded steel butt joint under Charpy impact test

MATEC Web of Conferences ◽

10.1051/matecconf/201713006003 ◽

2017 ◽

Vol 130 ◽

pp. 06003

Author(s):

Jianli Li ◽

Yalan Zhao ◽

Yingying Li ◽

Min You

Keyword(s):

Layer Thickness ◽

Impact Test ◽

Charpy Impact ◽

Charpy Impact Test ◽

Butt Joint ◽

Main Layer

Download Full-text

A New Fracture Analysis Technique for Charpy Impact Test Using Image Processing

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2021.59.1.61 ◽

2021 ◽

Vol 59 (1) ◽

pp. 61-66

Author(s):

Tae Chang Park ◽

Beom Suk Kim ◽

Ji Hee Son ◽

Yeong Koo Yeo

Keyword(s):

Image Processing ◽

Brittle Fracture ◽

Ductile Fracture ◽

Impact Test ◽

Charpy Impact ◽

Charpy Impact Test ◽

Fracture Analysis ◽

Binary Image ◽

Fracture Area ◽

Brittle Fractures

The Charpy impact test is used to identify the transition between ductility and brittleness. The percentages of ductile and brittle fractures in steel can be evaluated based on each fracture area, which is presently determined by an analyzer with the naked eye. This method may lead to subjective judgement, and difficulty accurately quantifying the percentage. To resolve this problem, a new analysis method based on image processing is proposed in this study. A program that can automatically calculate the percentage of the ductile and brittle fractures has been developed. The analysis is performed after converting an RGB fracture image into a binary image using image processing techniques. The final binary image consists of 0 and 1 pixels. The parts with the pixel values of 1 correspond to the brittle fracture areas, and the pixel values of 0 represent the ductile fracture areas. As a result, by counting the number of 0 pixels in the entire area, it is possible to automatically calculate the percentage of ductile fracture. Using the proposed automatic fracture analysis program, it is possible to selectively distinguish only the brittle fracture from the entire fracture area, and to accurately and quantitatively calculate the percentages of ductile and brittle fractures.

Download Full-text