scholarly journals Investigations on arc brazing for galvanized heavy steel plates in steel and shipbuilding

2021 ◽  
Author(s):  
Philipp Andreazza ◽  
Andreas Gericke ◽  
Knuth-Michael Henkel
Keyword(s):  
Low Cost ◽  
Thin Sheet ◽  
Steel Structures ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Steel Plates ◽  
Galvanized Steel ◽  
Filler Materials ◽  
Static Tensile ◽  
Brazed Joints

AbstractArc brazing with low-melting copper-based filler materials, which has long been established and standardized in the thin sheet sector, offers numerous advantages in the processing of predominantly electrolytically galvanized steel structures. In steel and shipbuilding, on the other hand, equipment parts made of thick steel sheets are hot-dip galvanized at low cost and with good corrosion-inhibiting properties. Quality welding of such constructions is not possible without special precautions such as removing the zinc layer and subsequent recoating. With regard to greater plate thicknesses, arc brazing was analyzed in these investigations as an alternative joining method with regard to its suitability for practical use. Within the scope of the investigations, CuSi3Mn, CuMn12Ni2, and four different aluminum bronzes were examined on different sheet surface conditions with regard to the geometrical and production parameters. This was carried out by build-up and connection brazing, executed as butt and cross joints. Quasi-static tensile tests and fatigue tests were used to assess the strength behavior. In addition, metallographic analyses are carried out as well as hardness tests. The suitability for multi-layer brazing and the tendency to distortion were also investigated, as well as the behavior of arc brazed joints under corrosive conditions.

scholarly journals The Effect of Copper and Brass on Friction Stir Welded Dissimilar Aluminium Alloy When Used as in Thin Sheet Form

2016 ◽  
Vol 45 (2) ◽  
pp. 118-122
Author(s):  
G. Gopala Krishna ◽  
P.Ram Reddy ◽  
M.Manzoor Hussain
Keyword(s):  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Low Cost ◽  
Thin Sheet ◽  
Welding Process ◽  
Cost Effective ◽  
Tensile Tests ◽  
Fusion Welding ◽  
Friction Stir ◽  
Effect Of Copper

In recent year’s aluminium and aluminium alloys are most widely used in many applications because of light weight, good formability and malleability, corrosion resistance, moderate strength and low cost. Friction Stir Welding (FSW) process is efficient and cost effective method for welding aluminium and aluminium alloys. FSW is a solid state welding process that means the material is not melted during the process. Complete welding process accomplishes below the melting point of materials so it overcomes many welding defects that usually happens with conventional fusion welding technique which were initially used for low melting materials. Though this process is initially developed for low melting materials but now process is widely used for a variety of other materials including titanium, steel and also for composites. The present butt jointed FSW experimental work has been done in two ways. Initially a comparison of tensile properties of friction stir (FS) welded similar aluminium alloy (AA6351 with AA6351) and dissimilar aluminium alloy (AA6351 with AA5083) combinations. Later the effect of impurities (copper and brass) in sheet form (0.1 mm thick) when used as insert in between two dissimilar aluminium alloy (AA6351 with AA5083) plates during FSW. Tensile tests were performed for these combinations and results were compared for with and without using strip material (copper and brass).

Mechanical Properties of Flat Braided Composites With a Circular Hole

1999 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Circular Hole ◽  
Fracture Behavior ◽  
Fatigue Property ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Braided Composites ◽  
Static Tensile ◽  
The One

Abstract In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two type of specimens were prepared. They are a braided flat bar with an integrally-formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole.

Mechanical Properties of Flat Braided Composites With a Circular Hole

2000 ◽  
Vol 122 (4) ◽  
pp. 420-424 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Circular Hole ◽  
Fracture Behavior ◽  
Fatigue Property ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Braided Composites ◽  
Static Tensile ◽  
The One

In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two types of specimen were prepared. They are a braided flat bar with an integrally formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole. [S0094-4289(00)02604-9]

Effect of transverse reinforcement on cracking of CFRP composite laminates under static and fatigue loads

2020 ◽  
Vol 54 (25) ◽  
pp. 3755-3766 ◽  
Author(s):  
Maciej Giżyński
Keyword(s):  
Composite Laminates ◽  
Crack Density ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Transverse Reinforcement ◽  
Damage Growth ◽  
Cfrp Laminates ◽  
Cfrp Composite ◽  
Static Tensile

Several CFRP laminates with various layups, possessing two distinctive forms of transverse reinforcement either UD 90° or fabric 0°/90°, were tested in both static and fatigue tests. All examined layups were considered to be used in the wingbox design of the multipurpose turboprop aircraft. In-situ microscopic observations were carried out during the tests. Static tensile tests allowed to find the strength of the laminas, stress, and strains at which cracks started to propagate, crack density during the test. The microscopic observations allowed to establish cracks’ growth paths. The first crack in laminates having fabric 0°/90° laminas usually was observed for higher stress and strain than in laminates with UD 90° laminas. Also, the later ones showed a tendency to significantly delaminate along the interface between UD 90° and UD 45° laminas. The fatigue test was carried out in order to find how to distinguish damage growth in both families of laminates that affects their fatigue life. As an outcome, S-N lines were determined. During the test the microscopic observations were made, which allowed to show crack and delamination growth during successive load cycles. The microscopic observations showed that cyclic loading leads to the fast growth of delaminations at the interface of fabric 0°/90°ply or UD 90° laminas.

Tensile and Fatigue Testings of Hybrid Al/APC-2 Nanocomposite Laminates at Elevated Temperature

2008 ◽  
Vol 47-50 ◽  
pp. 592-595 ◽  
Author(s):  
Ming Hwa R. Jen ◽  
Yi Chun Sung ◽  
Yin Da Lai
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Thermoplastic Matrix ◽  
Longitudinal Stiffness ◽  
Hybrid Laminates ◽  
Static Tensile ◽  
Aluminum Alloy 2024 ◽  
Strength And Stiffness

To deal with the stringent operational demands the aerospace structural materials of light weight Aluminum alloy 2024 sheets and plies of carbon fibers reinforced thermoplastic matrix PEEK were used to sustain at least 80% of their mechanical properties at elevated temperature. The addition of nanoparticles SiO2 can enhance the composite laminate strength and stiffness. Also, Al 2024 sheets were treated by an anodic method of electroplating to increase surface roughness to achieve perfectly bonding with matrix PEEK. Then, the modified diaphragm curing process was adopted to make the innovative hybrid Al/APC-2 hybrid nanocomposite laminates. Next, both static tensile and fatigue tests were conducted at elevated temperature to obtain the mechanical properties, lives and failure mechanisms to verify the improved features of hybrid specimens. From tensile tests the mechanical properties of Al/APC-2 [4Al/0/±45/90/2Al]s hybrid laminates at elevated temperature were obtained. Although there is a big drop at 150°C, the reduction in strength from RT to 125°C is generally not significant. The longitudinal stiffness is almost unchanged at elevated temperature. After cyclic tension-tension (T-T) tests, the positions of received S-N curves go downwards as temperature rising. No delaminations were found in both tests. If the applied stress normalized by the ultimate strength at corresponding temperature, the normalized S-N curves are closer with some curve positions reversed. Significant improvement of manufacturing and enhancement of mechanical properties in hybrid laminates were achieved finally.

A Two Dimensional Phenomenological Model for Damage of Arteries

2007 ◽  
Author(s):  
Alexander Rachev
Keyword(s):  
Mechanical Strength ◽  
Vascular Tissue ◽  
Longitudinal Direction ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Traumatic Rupture ◽  
Artery Graft ◽  
Arterial Tissue ◽  
Static Tensile ◽  
Failure Properties

Loss of mechanical strength of arteries can manifest itself in many ways including rupture of a vulnerable atherosclerotic plaques, burst of saccular aneurisms, rupture of artery/graft anastomosis, and traumatic rupture of aorta by impact loading due to automobile accidents. In all cases the fracture of the tissue leads to sudden cardiovascular events that often have a lethal end. To date there are insufficient experimental data on the mechanical strength of healthy and diseased vascular tissue. Most of the results refer to the failure properties from uniaxial quasi-static tensile tests on strips and rings. It was found that the tensile strength is different in the circumferential and longitudinal direction especially when it is determined from strain controlled dynamic tests [1]. Results form load-controlled fatigue tests have shown a gradual softening of the arterial tissue, development of a residual (plastic) deformation, and existence of S-N curve [2]. However, the information from uniaxial tests is not sufficient to predict the damage of tubular segments due to coupling between circumferential and longitudinal stress via constitutive equations and deformed geometry. Moreover, the mechanisms of arterial tissue failure remain unknown.

scholarly journals The Environmental Impact of Ecological Rehabilitation Techniques Applied to Statically and Variably Stressed Welded Structures

2018 ◽  
Vol 10 (12) ◽  
pp. 4782
Author(s):  
Oana Roxana Chivu ◽  
Claudiu Babis ◽  
Augustin Semenescu ◽  
Olivia Doina Negoita ◽  
Gabriel Iacobescu ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Hsla Steel ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Filler Materials ◽  
Variable Load ◽  
Low Alloy Steels ◽  
Welded Structures ◽  
Ecological Rehabilitation ◽  
Weld Toe

There are many welded structures in the world such as bridges and viaducts that are subject to fatigue. Some of these structures, generally made of non-alloy or low-alloy steels, have been put into operation many years ago and have accumulated a large number of variable load cycles over time. For this reason, the occurrence of the fatigue phenomenon is inevitable and consists in the occurrence of failures at stresses applied to the structure, below the yield limit of the material. These stresses under the static loads would not cause the failures to appear. This paper will investigate if the ecological reconditioning techniques “weld toe grinding” and “WIG re-melting weld toe,” influence favourably the behaviour of the welded structures made from HSLA steel, in static and variable loads, if the application of these techniques is justified in both cases and finally which is the environmental impact of applying these techniques. In the paper we will present the chemical composition and mechanical properties of the base and filler materials, micro and macrostructures, graphics with the variation of the micro-hardness, we will perform static and fatigue tensile tests and we will rise the durability curve in the case of the fatigue tests. We will also present a mathematical computational algorithm, which highlights the extent to which these ecological rehabilitation techniques pollute the environment. It is more efficient both for technological and ecological reasons to recondition a product than to manufacture it from the very beginning.

scholarly journals Assessment of the quality of abrasion-resistant plates welded joint

2020 ◽  
Vol 56 (2) ◽  
pp. 209-220
Author(s):  
J. Górka
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Filler Metal ◽  
Base Material ◽  
Tensile Tests ◽  
Filler Materials ◽  
Metal Arc Welding ◽  
The Face ◽  
Static Tensile ◽  
Chromium Cast Iron

The article presents the analysis of the structure and properties of joints made of abrasion-resistant plates having the structure of chromium cast iron and welded with filler metals, the use of which aimed to provide the high abrasion resistance of the surface layer and good mechanical properties of the base material. The face layer of the joint was made using the MMA (Manual Metal Arc) welding method and the Fe-Cr-Nb-B type nanocrystalline filler metal. The root weld was welded using an austenitic filler metal, whereas the filling layer was welded using the MAG method with a low-alloy filler metal. The joints were subjected to non-destructive tests (visual tests and penetrant tests) as well as to mechanical properties tests. The research involved macro and microscopic metallographic tests, the determination of the grain size using an Xpert PRO X-ray diffractometer, and the EDS analysis of the chemical composition of the precipitates. The assessment of the operational properties of the joints based on hardness measurements, static tensile tests, bend tests as well as identifying the metal-mineral abrasive wear resistance were performed in accordance with ASTM G65 ? 04 standards. The results of the abrasion resistance tests were referred to the HARDOX 400 steel reference specimen. Considering the tests results it was concluded that the used filler materials can assure the appropriate operational properties of welded abrasion-resistant plates.

MODE I STRESS INTENSITY FACTOR OF CENTER-CRACKED TENSILE STEEL PLATES WITH CFRP REINFORCEMENT

2013 ◽  
Vol 13 (01) ◽  
pp. 1350005 ◽  
Author(s):  
CHAO WU ◽  
XIAO LING ZHAO ◽  
RIADH AL-MAHAIDI ◽  
WEN HUI DUAN
Keyword(s):  
Stress Intensity ◽  
Steel Plate ◽  
Steel Structures ◽  
Fatigue Tests ◽  
Steel Plates ◽  
Mode I ◽  
Reinforced Polymer ◽  
Single Side ◽  
Geometric Factors ◽  
Parametric Studies

Advanced carbon fiber reinforced polymer (CFRP) demonstrates promise for the fatigue strengthening of steel structures. By decreasing the stress field at the crack tip, the stress intensity factors (SIFs) can be effectively reduced by CFRP reinforcement. In this paper, the mode I SIF of CFRP-reinforced center-cracked tensile (CCT) steel plate is proposed based on a series of fatigue tests. The selected fatigue tests include experiments conducted by the authors as well as fatigue tests reported in the literature, covering different CFRP systems (low/high modulus, CFRP sheeting/plate) with various CFRP strengthening dimensions. The classical mode I SIF of CCT steel plate without CFRP strengthening is selected as the basis of the proposed solution. Then two reduction factors, similar to the correction factors given in the Japanese Society of Steel Construction (JSSC) standard, are introduced to study the effects of the mechanical properties of CFRP composites and the geometries of the CFRP reinforcement, respectively. Modified SIFs for both single-side CFRP-reinforced and double-side CFRP-reinforced CCT steel plates are proposed. It is found that the experimental SIFs of CFRP-reinforced CCT steel plates can be reasonably captured by the proposed mode I SIF formula. Finally, parametric studies for investigating the sensitivity of SIF to various mechanical and geometric factors are presented.

Adhesive Strength between Flexible Hydroxyapatite Sheet and Tooth Enamel

2012 ◽  
Vol 529-530 ◽  
pp. 522-525 ◽  
Author(s):  
Ei Yamamoto ◽  
Nobuhiro Kato ◽  
Hiroaki Nishikawa ◽  
Masanobu Kusunoki ◽  
Takashi Hayami ◽  
...  
Keyword(s):  
Adhesive Strength ◽  
Tooth Enamel ◽  
Thin Sheet ◽  
Electron Microscopic Observation ◽  
Tensile Tests ◽  
Phosphate Solution ◽  
Curved Surfaces ◽  
Electron Microscopic ◽  
Human Teeth ◽  
Static Tensile

Tooth enamel cannot be reconstructed once it is destroyed immoderately. Hydroxyapatite (HAp) thin sheet can potentially be used for a novel dental biomaterial to repair the enamel. Using a pulsed laser deposition (PLD) method, we have successfully created a flexible HAp sheet of less than a few micrometers in thickness. Due to its flexibility, the HAp sheet is tightly adhered on curved surfaces at the target site. In the present study, we newly developed double-layered sheets composed of HAp film coated with tricalcium phosphate (TCP) thin layer. The HAp/TCP sheet was adhered to the extracted human teeth using a calcium phosphate solution for 3 days. The adhesive strength between the HAp/TCP sheet and tooth enamel was evaluated by quasi-static tensile tests. Moreover, the interface structure between them was observed by a scanning electron microscopy. As a result of the mechanical evaluation, the adhesive strength was greater than approximately 2.5 MPa. The electron microscopic observation revealed that the sheet was partially fused with the enamel. These findings suggest the possibility that enamel defects are repaired using the HAp/TCP sheet for a short duration.

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