The Analysis of the Test Results Base on the Performance Sample Processing Differences

2012 ◽  
Vol 197 ◽  
pp. 337-341
Author(s):  
Dai Lu Zhang ◽  
Shi Jun Hu ◽  
Hong Xiang Zhang

In the mechanical properties test, in order to ensure test results reflect the characteristics of the material itself reliably, the sample’s quality of processing is an essential prerequisite. Performance sample with different shapes were processed into different diameters, different shoulder of the transition area, and different width, to be conducted with tensile tests of mechanical properties. The results show that differences in sample processing on the mechanical test results are different, and we fine some disciplines by analyzing the reasons causing the differences.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1671
Author(s):  
Mohd Shahneel Saharudin ◽  
Jiri Hajnys ◽  
Tomasz Kozior ◽  
Damian Gogolewski ◽  
Paweł Zmarzły

The paper presents the results of mechanical tests of models manufactured with two 3D printing technologies, FDM and CFF. Both technologies use PLA or PA-based materials reinforced with carbon fibers. The work includes both uniaxial tensile tests of the tested materials and metrological measurements of surfaces produced with two 3D printing technologies. The test results showed a significant influence of the type of technology on the strength of the models built and on the quality of the technological surface layer. After the analysis of the parameters of the primary profile, roughness and waviness, it can be clearly stated that the quality of the technological surface layer is much better for the models made with the CFF technology compared to the FDM technology. Furthermore, the tensile strength of the models manufactured of carbon fiber-enriched material is much higher for samples made with CFF technology compared to FDM.


Author(s):  
Leila Ladani ◽  
Lalit Roy

Additive Layer Fabrication, in particular Electron Beam Additive Fabrication (EBAF), has recently drawn much attention for its special usability to fabricate intricately designed parts as a whole. It not only increases the production rate which reduces the production lead time but also reduces the cost by minimizing the amount of waste material to a great extent. Ti6Al4V is the most common type of material that is currently being fabricated using EBAF technique. This material has been used in aerospace industry for several reasons such as excellent mechanical properties, low density, great resistance to corrosion, and non-magnetism. The effects of build direction of layers (namely, addition of layers along one of the x, y & z directions with respect to the build table) and the anisotropy effect caused by it has not been explored vigorously. This anisotropy effect has been investigated in this work. Different mechanical properties such as Yield Strength (YS), Ultimate Tensile Strength (UTS), and Modulus of Elasticity (E) of these three types of Ti6Al4V are determined using tensile tests and are compared with literature. The tensile test results show that YS and UTS for flat-build samples have distinguishably higher values than those of the side-build and top-build samples.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hui Chen ◽  
Jinjin Zhang ◽  
Jin Yang ◽  
Feilong Ye

The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. The present paper studies the mechanical behavior of the corroded high strength reinforcing steel bars under static and dynamic loading. High strength reinforcing steel bars were corroded by using accelerated corrosion methods and the tensile tests were carried out under different strain rates. The results showed that the mechanical properties of corroded high strength steel bars were strain rate dependent, and the strain rate effect decreased with the increase of corrosion degree. The decreased nominal yield and ultimate strengths were mainly caused by the reduction of cross-sectional areas, and the decreased ultimate deformation and the shortened yield plateau resulted from the intensified stress concentration at the nonuniform reduction. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion degree and strain rate for corroded bars. A modified Johnson-Cook strength model of corroded high strength steel bars under dynamic loading was proposed by taking into account the influence of corrosion degree. Comparison between the model and test results showed that proposed model properly describes the dynamic response of the corroded high strength rebars.


2019 ◽  
Vol 131 ◽  
pp. 01127
Author(s):  
Wen Wen Yu ◽  
Jian Gao Shi ◽  
Yong Li Liu ◽  
Lei Wang

Ultra-high molecular weight polyethylene (UHMWPE) and graphene (GR) was melt compounded by reactive extrusion. Nanocomposite monofilaments were prepared by melt spinning through a co-rotating screw extruder and drawing at hot water. GR/UHMWPE nanocomposite ropes were twisted using nanocomposite monofilaments. A structure and mechanical properties of the GR/UHMWPE nanocomposite monofilaments and its ropes had been characterized by scanning electron microscopy (SEM), and mechanical test. Results showed that the monofilaments surface of monofilaments became rougher with introducing of GR nanosheets, which could be related to stacking of GR. The breaking load of GR/UHMWPE nanocomposite ropes was remarkably improved upon nanofiller addition, with the decrease of the elongation at break.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4801
Author(s):  
Yasir Khaleel Kirmasha ◽  
Mohaiman J. Sharba ◽  
Zulkiflle Leman ◽  
Mohamed Thariq Hameed Sultan

Fiber composites are known to have poor through-thickness mechanical properties due to the absence of a Z-direction binder. This issue is more critical with the use of natural fibers due to their low strength compared to synthetic fibers. Stitching is a through-thickness toughening method that is used to introduce fibers in the Z-direction, which will result in better through-thickness mechanical properties. This research was carried out to determine the mechanical properties of unstitched and silk fiber-stitched woven kenaf-reinforced epoxy composites. The woven kenaf mat was stitched with silk fiber using a commercial sewing machine. The specimens were fabricated using a hand lay-up method. Three specimens were fabricated, one unstitched and two silk-stitched with deferent stitching orientations. The results show that the stitched specimens have comparable in-plane mechanical properties to the unstitched specimens. For the tensile mechanical test, stitched specimens show similar and 17.1% higher tensile strength compared to the unstitched specimens. The flexural mechanical test results show around a 9% decrease in the flexural strength for the stitched specimens. On the other hand, the Izod impact mechanical test results show a significant improvement of 33% for the stitched specimens, which means that stitching has successfully improved the out-of-plane mechanical properties. The outcome of this research indicates that the stitched specimens have better mechanical performance compared to the unstitched specimens and that the decrease in the flexural strength is insignificant in contrast with the remarkable enhancement in the impact strength.


Author(s):  
C. Senfuka ◽  
J. B. Kirabira ◽  
J. K. Byaruhanga

All steel made in Uganda is currently manufactured from scrap. Such steel has often been characterized by unpredictable performance in consonance with its inconsistent raw material inputs. This study evaluates and relates the mechanical, metallurgical and geometrical properties of these bars in order to identify the factors underlying the performance of the products from this steel and examine the relationship with their scrap content. In order to study the steels, tensile, torsion and micrographic tests have been carried out together with spark emission spectrometry on samples collected from different plants. The test results generally indicate impressive steel resilience, strength and metallographic properties in spite of relatively high and irregular carbon content. Limited weldability, uniaxiality of properties, uneven scatter of microelements and substantial non-uniformity of longitudinal mechanical properties have been observed. Rolling and post rolling defects have been noted. The geometric reliability of the bars has also been found generally low. Improvement of secondary refinement, use of direct reduced iron (DRI) diluent and more diligent sorting have suggested as solutions.


1991 ◽  
Vol 239 ◽  
Author(s):  
Martha K. Small ◽  
Joost J. Vlassak ◽  
William D. Nix

ABSTRACTSince its first application to thin films in the 1950's, the bulge test has had a prominent place in the field of thin film mechanical properties. The major appeal of the technique is that it is analogous to the familiar uniaxial tension test, which is commonly applied to bulk materials. At the same time, it avoids the sample tearing and alignment problems associated with micro-tensile tests. Unfortunately, bulge test results have been sometimes controversial and difficult to reproduce. In this paper we address possible causes for mese inconsistencies and describe a method by which the bulge test technique can be made to produce accurate and reliable results.


2016 ◽  
Vol 1138 ◽  
pp. 19-24
Author(s):  
Mihailo Mrdak ◽  
Nikola Bajić ◽  
Marko Rakin ◽  
Darko Veljić ◽  
Zoran Karastojković ◽  
...  

The paper presents test results of a new quality of a special rutile electrode, with a core of flux-cored wire made from local raw materials, based on analyzing mechanical properties and microstructure of the weld metal in MMA welding. The base metal for experimental welding was microalloyed steel marked J55 (thickness 7.0 mm) according to API Spec 5L standards (EN 10113-3. and JUS C.B0 502) which was produced in Smederevo steelworks. For experimental welding a special electrode IHIS E 35 R-2 was used, with a medium thickness rutile coating, a core of flux-cored wire and Ni content of 2.5%. The results of the analyzes indicate that the new quality special rutile electrode with the flux-cored wire core provides good structural and mechanical properties of weld metal in microalloyed steel welded joints.


2013 ◽  
Vol 353-356 ◽  
pp. 20-23
Author(s):  
Xiao Lei Wang ◽  
Shun Xi Yan ◽  
Guang Can Zhang

According to the problemsof serious deformation of soft rock roadways and lack of system andcomprehensive study on surrounding rock characteristics and failure mechanismin Shajihai mining area, this paper carried out a series of mechanicalexperiments on the characteristics of surrounding rock in this area includinguniaxial compression test, triaxial compression test and water absorption propertiestest. Mechanical test results show that the compressive strength of surroundingrock of roadway is generally low, and mudstone compressive strength is thelargest which is 19.23 MPa, and compressive strength of the minimum is coalwhich is 11.32 MPa under natural condition. However sandstone and mudstone’sability of water absorbing is strong, and coal saturation strength issignificantly greater than that of mudstone and sandstone. Therefore, we shouldmake full use of the strength of coal in roadway layout and support design.


2015 ◽  
Vol 1129 ◽  
pp. 169-176
Author(s):  
Sunhee Hong ◽  
Wan Ki Kim

This study is to examine and clarify the quality of polymer-modified mortars using a VA/E/MMA terpolymer powder as compared with polymer-modified mortars using a VAE copolymer powder. Polymer-modified mortars using general commercial redispersible polymer powders are prepared with various polymer-cement ratios, and tested for flexural and compressive strengths, tensile strength, water absorption, chloride ion penetration, carbonation and pore size distribution by mercury porosimetry. Overall, the properties of polymer-modified mortars using a VA/E/MMA terpolymer powder were superior to those of polymer-modified mortars using a VAE copolymer powder. And VA/E/MMA terpolymer powder-modified mortars showed significantly improved mechanical properties and durability in comparison with unmodified mortar. It is concluded from the test results that the modification of cement mortar with redispersible polymer powder improves the properties of unmodified mortar, and VA/E/MMA terpolymer powder has higher quality than VAE copolymer powder.


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