Investigation of Residual Stresses Distribution in Titanium Weldments

2014 ◽  
Vol 777 ◽  
pp. 171-175 ◽  
Author(s):  
Shao Pin Song ◽  
Anna M. Paradowska ◽  
Ping Sha Dong
Keyword(s):  
Residual Stresses ◽  
High Performance ◽  
Weight Ratio ◽  
Welding Process ◽  
High Strength ◽  
Naval Research ◽  
Office Of Naval Research ◽  
And Performance ◽  
Superior Corrosion Resistance ◽  
The University

Titanium and its alloys have increasingly become a material of choice for applications in high-performance structures due to their superior corrosion resistance and high strength-to-weight ratio. However, in contrast to conventional steel alloys, there exist little design and manufacturing experience in the heavy fabrication industry with large welded structures made of titanium materials. In addressing the above concern, the University of New Orleans funded by Office of Naval Research (ONR) initiated program on investigation of manufacturability and performance of a titanium mid-ship section. The uniqueness of this program is its focus upon a representative full-size mid-ship section upon which relevant scientific and technological challenges are simulated and experimentally validated. This paper reports the measurements of residual stresses using neutron diffraction in titanium T-joints. The residual stresses were measured using Engin-X at ISIS (UK) and the Kowari Strain Scanner at ANSTO (Australia). This experimental research was used to validate our in house predictions and significantly improved the knowledge and understanding of the welding process of titanium alloys.

An Improved Size, Matching, and Scaling Method for the Design of Deterministic Mesoscale Truss Structures

2011 ◽  
Author(s):  
Patrick S. Chang ◽  
David W. Rosen
Keyword(s):  
High Performance ◽  
Design Method ◽  
Weight Ratio ◽  
High Strength ◽  
Original Method ◽  
Topological Optimization ◽  
Truss Structures ◽  
Scaling Method ◽  
Element Analysis ◽  
And Performance

Mesoscale truss structures are cellular structures that have support elements on the order of centimeters. These structures are engineered for high performance and have applications in industries where a high strength-to-weight ratio is desired. However, design of mesoscale truss structures currently requires some form of topological optimization that slows the design process. In previous research, a new Size, Matching and Scaling method was presented that eliminated the need for topological optimization by using a solid-body finite element analysis combined with a library of lattice configurations to generate topologies. When compared to topological optimization, results were favorable: design times were significantly reduced and performance results were comparable. In this paper, we present a modified Size Matching and Scaling design method that addresses key issues in the original method. Firstly, we outline an improve methodology. Secondly, we expand the library of configurations in order to improve lattice performance. Finally, we test the updated method and library against design examples.

scholarly journals Weldability Investigation and Optimization of Process Variables for TIG-Welded Aluminium Alloy (AA 8006)

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
T. Sathish ◽  
S. Tharmalingam ◽  
V. Mohanavel ◽  
K. S. Ashraff Ali ◽  
Alagar Karthick ◽  
...  
Keyword(s):  
Experimental Design ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Surface Hardness ◽  
Weight Ratio ◽  
Welding Process ◽  
Tig Welding ◽  
Low Weight ◽  
Superior Corrosion Resistance ◽  
Welding Processes

Aluminium and its alloys play a significant role in engineering material applications due to its low weight ratio and superior corrosion resistance. The welding of aluminium alloy is challenging for the normal conventional arc welding processes. This research tries to resolve those issues by the Tungsten Inert Gas welding process. The TIG welding method is an easy, friendly process to perform welding. The widely applicable wrought aluminium AA8006 alloy, which was not considered for TIG welding in earlier studies, is considered in this investigation. For optimizing the number of experiments, the Taguchi experimental design of L9 orthogonal array type experimental design/plan was employed by considering major influencing process parameters like welding speed, base current, and peak current at three levels. The welded samples are included to investigate mechanical characterizations like surface hardness and strengths for standing tensile and impact loading. The results of the investigation on mechanical characterization of permanent joint of aluminium AA8006 alloy TIG welding were statistically analyzed and discussed. The 3D profilometric images of tensile-tested specimens were investigated, and they suggested optimized process parameters based on the result investigations.

Comparison between Modelled Influence of GMAW Parameters and Corresponding Mechanical Properties of Group 1 and 2 According to ISO/TR 15608 Steel T Joints

2021 ◽  
Vol 890 ◽  
pp. 17-24
Author(s):  
Aurel Valentin Bîrdeanu ◽  
Alin Constantin Murariu ◽  
Horia Florin Daşcău ◽  
Iuliana Duma
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Hsla Steel ◽  
Welding Process ◽  
High Strength ◽  
Industrial Applications ◽  
Steel Plates ◽  
Experimental Program ◽  
Welding Parameters ◽  
T Joints

Reproducibility in respect to welded structures realization is one of the main requirements for a wide variety of industrial applications. One of the international tendencies regarding the use of the steel is the replacing, in critical areas, of structural steels with high performance steel, e.g. with HSLA steels. The paper presents the results of a factorial designed experimental program focused on determining mathematical correlations between the GMAW process parameters for T joints of 4mm thick steel plates of structural (S235JR+AR according to SR EN 10025-2) and hot-rolled, high-strength low-alloy (HSLA) steel plates (S420MC according to EN 10025-4), respectively. A comparison between the obtained mathematical correlations that connect the welding parameters and the main mechanical characteristics is presented. The correlations can be used for applying the optimal combination of welding process parameters for realizing the T-joints of welded products.

scholarly journals Ground Glass Pozzolan in Conventional, High, and Ultra-High Performance Concrete

2018 ◽  
Vol 149 ◽  
pp. 01005 ◽  
Author(s):  
Arezki Tagnit-Hamou ◽  
Ablam Zidol ◽  
Nancy Soliman ◽  
Joris Deschamps ◽  
Ahmed Omran
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Ground Glass ◽  
Strengthening Effect ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Supplementary Cementitious Material ◽  
Pozzolanic Material ◽  
And Performance

Ground-glass pozzolan (G) obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM), given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC), high-performance concrete (HPC), and ultra-high performance concrete (UHPC). The current paper reports on the characteristics and performance of G in these concrete types. The use of G provides several advantages (technological, economical, and environmental). It reduces the production cost of concrete and decrease the carbon footprint of a traditional concrete structures. The rheology of fresh concrete can be improved due to the replacement of cement by non-absorptive glass particles. Strength and rigidity improvements in the concrete containing G are due to the fact that glass particles act as inclusions having a very high strength and elastic modulus that have a strengthening effect on the overall hardened matrix.

High-Performance Linear Cable Transmission

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Joan Savall ◽  
Javier Martín ◽  
Alejo Avello
Keyword(s):  
High Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Negative Effects ◽  
Low Friction ◽  
Alternative Design ◽  
Cable Length ◽  
High Stiffness ◽  
Length Changes

Cable transmissions offer several advantages such as high stiffness to weight ratio, high strength, low friction, and absence of backlash, which makes them appropriate for demanding mechanical applications. However, while extensively used as rotational transmissions, there are only a few examples of linear cable transmissions in the literature. The reason is that the up-to-date designs are based on a cable layout that leads to cable length changes during movement. This, in turn, produces negative effects such as transmission nonlinearity and cable fatigue. In this paper, an alternative design for linear cable transmissions is presented. The new design overcomes the aforementioned problems through a proper cable layout. Different applications of the new transmission are reported, validating the proposed design.

Self-driven Liquid Metal Mollusk Oscillations

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Tingting Hao ◽  
Wenyu Cui ◽  
Huiwen Yu ◽  
Xuehu Ma ◽  
Hongbin Ma
Keyword(s):  
Surface Tension ◽  
Liquid Metal ◽  
High Performance ◽  
Research Work ◽  
Water Film ◽  
Naval Research ◽  
Two Phase ◽  
Oscillating Heat Pipe ◽  
Office Of Naval Research ◽  
Field Disturbance

Abstract Room temperature liquid metal (galinstan, made up of gallium, indium and tin) is driven to oscillate by the phase change of water in the self-excited oscillating heat pipe (OHP) charged with liquid metal and water. The cross section of the channel is square with the dimension of 3×3 mm2. Liquid metal is a high-performance coolant with ultrahigh thermal conductivity (nearly 27 times higher than water). During the operation of OHP, liquid metal is pushed up by the vapor expansion in the evaporator section, and moves back by the vapor contraction and gravity effects. Then, liquid metal is driven to oscillate continuously between evaporator and condenser in the OHP. Surface tension of galinstan is 10 times higher than water, resulting in a ball shape of liquid metal in the channels. And there is a thin water film existing between liquid metal and inner surface. During the oscillating motion, liquid metal presents the characteristics of a mollusk. Soft liquid metal is extended into metal filament, or breaks up into small liquid metal balls. Then, small liquid metal balls coalesce into a long liquid metal slug, resulting in surface waves due to the released surface energy during the coalescence process. The deformation and deformation recovery of the liquid metal is the result of competition between deforming pressure forces and the reforming surface tension forces. Oscillations of liquid metal will generate flow field disturbance in the base fluid of water and further enhance the heat transfer performance in two-phase flow systems. [This research work was supported by the National Natural Science Foundation of China under Grant No. 21606034 and Office of Naval Research under Grant No. N00014-19-1-2006.]

Modeling the interrelationship between the parameters for improving weld strength in plastic hot plate welding: A DEMATEL approach

2019 ◽  
Vol 52 (2) ◽  
pp. 117-141
Author(s):  
K Mathiyazhagan ◽  
Krishna Kumar Singh ◽  
V Sivabharathi
Keyword(s):  
Product Design ◽  
Manufacturing Process ◽  
Weight Ratio ◽  
Welding Process ◽  
High Strength ◽  
Weld Strength ◽  
Melting Time ◽  
Hot Plate ◽  
Plate Temperature ◽  
Hot Plate Welding

Application of plastics is increasing day by day since plastics offer many distinct advantages as compared to metals. Plastics has mainly good thermal and electrical insulation properties, corrosion resistance, chemical inertness, and high strength to weight ratio. Additionally, these are cheaper in cost as compared to conventional materials. Plastics are additionally easy to process. Nowadays, product requirements are getting critical and thus product design is getting more complex in shape. To manufacture intricate complex shape creates complexity in manufacturing process which is sometimes very difficult or almost not feasible to produce with single manufacturing process. To manufacture such critical products, welding is a complimentary process. Type of weld joint and welding process can be selected based on the product design and load application on the product. Hot plate welding is very simple welding process as compared to other plastic welding process and most commonly used. Good quality weld is the prime objective of welding process. Weld strength is dependent on several parameters which may be process parameters as well as product parameters. The objective of this study is to identify the key parameters in hot plate welding process of the plastics using Decision Making Trial and Evaluation Laboratory which is one of the prioritization techniques. Results of the study focus on understanding the key parameters affecting the weld strength. Study shows that hot plate temperature, welding time, and melting time are the key parameters affecting the weld strength.

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