Criteria for Evaluating Bolt Head Design

1976 ◽  
Vol 98 (4) ◽  
pp. 1179-1182
Author(s):  
R. C. Landt
Keyword(s):  
Mechanical Properties ◽  
Design Procedure ◽  
Critical Factors ◽  
Significant Area ◽  
Bolt Failure ◽  
Material Utilization ◽  
Joint Integrity

The emphasis on reducing fastener weight, conserving material, and providing joint integrity has increased the importance of understanding the causes of bolt failure. In bolt design, a significant area where better material utilization can be achieved is the bolt head. This paper identifies the critical factors in head design which affect mechanical properties and presents a design procedure to determine the optimum head configuration.

A Study on the Micro Property Testing of Micro Embossing Patterned Metallic Thin Foil

2007 ◽  
Vol 345-346 ◽  
pp. 335-338
Author(s):  
Hye Jin Lee ◽  
Nak Kyu Lee ◽  
Hyoung Wook Lee
Keyword(s):  
Mechanical Properties ◽  
Optimal Design ◽  
Design Procedure ◽  
Thin Foil ◽  
Property Testing ◽  
Rolling Process ◽  
Industrial Technology ◽  
Cold Isostatic Press ◽  
Nano Indentation ◽  
Thin Foils

In this paper, Experimental results on the measurement of mechanical properties of fine patterns in the MEMS structure are described. The mechanical properties of embossing patterns on metallic thin foil is measured using the nano indentation system, that is developed by Korea Institute of Industrial Technology(KITECH). These micro embossing patterns are fabricated using CIP(Cold Isostatic Press) process on micro metallic thin foils(Al-1100) that are made by rolling process. These embossing patterned metallic thin foils(Al-1100) are used in the reflecting plate of BLU(Back Light Unit) and electrical/mechanical MEMS components. If these mechanical properties of fine patterns are utilized in a design procedure, the optimal design can be achieved in aspects of reliability as well as economy.

Microstructural administered mechanical properties and corrosion behaviour of wire plus arc additive manufactured SS 321 plate

2021 ◽  
pp. 095440622110420
Author(s):  
S Mohan Kumar ◽  
R Sasikumar ◽  
A Rajesh Kannan ◽  
R Pramod ◽  
N Pravin Kumar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Behaviour ◽  
Film Formation ◽  
Vertical Direction ◽  
Dendritic Microstructure ◽  
Aisi 321 ◽  
Mechanical Properties And Corrosion ◽  
Corrosive Environments ◽  
Material Utilization ◽  
The Impact

Wire plus arc additive manufacturing (WAAM) technology with higher deposition rate and efficient material utilization was employed to fabricate a stainless steel 321 (SS 321) wall for the first time. In this work, the microstructural characteristics, mechanical properties and corrosion performance of as-built SS 321 were evaluated. The micrographs confirmed the presence of columnar and equiaxed dendrites along the building direction, and recrystallization of grains was noticed due to the re-melting of former layers. The microstructure was dominantly austenite with a small fraction of ferrite within the austenitic matrix. Better tensile properties were noticed for as-printed SS 321 WAAM samples in-comparison to wrought counterpart. This is corroborated to the equiaxed and columnar dendritic microstructure with small fraction of ferrite (FN). The hardness decreased from bottom (247 HV) to top (196 HV) region in SS 321 WAAM plate and is attributed to the microstructural difference with varying amount of ferrite (6.3 to 3.7 FN). The impact strength of samples in the horizontal and vertical direction was 116  ±  2 J and 114  ±  2.5 J respectively, and is comparable with the wrought AISI 321 (123  ±  1.5 J). The reduction in impact toughness is attributed to the ferrite (<6.3 FN) fraction. Polarization curves and Nyquist plots elucidate the excellent pitting resistance of SS 321 WAAM specimens, and the corrosion rate was less than 1 mils per year (mpy). Corrosion cracks were absent, and the passive film formation in the WAAM specimens were compact and highly stable for corrosive environments.

Inertia Welded Jet Engine Components

1971 ◽  
Author(s):  
K. W. Stalker ◽  
L. P. Jahnke
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Titanium Alloys ◽  
Jet Engine ◽  
Mechanical Joints ◽  
Material Utilization ◽  
The Cost ◽  
Engine Components ◽  
Solid State Joining ◽  
Joining Process

The fabrication of jet engine rotors by joining simple disk and ring shapes offers both weight and cost advantages; however, the metal joints must have excellent and completely reproducible mechanical properties. Inertia welding achieves this since it is a solid state joining process which forges the two parts together under an automatically controlled situation. The parameters for inertia welding jet engine nickel and titanium alloys are discussed. The cost and weight advantages occurring from elimination of mechanical joints and better material utilization are identified. Several typical applications are described.

Structural and Technology Support Quality Improvement of Gear Coupling

2013 ◽  
Vol 371 ◽  
pp. 3-7
Author(s):  
Aleksandr Mikhaylov ◽  
Roman Grubka ◽  
Aleksey Lahin ◽  
Alexander Nedashkovskiy ◽  
Ahmed Guitouni
Keyword(s):  
Mechanical Properties ◽  
Quality Improvement ◽  
Mechanical Treatment ◽  
Design Procedure ◽  
Treatment Method ◽  
Geometric Parameters ◽  
Technology Support ◽  
Kinematic Method ◽  
Thermo Mechanical Treatment

In this work the question of sharing use a thermo-mechanical treatment method and forming spatial tool based on a kinematic method researches gearings, is considered. Also, the method of thermo mechanical treatment a gear couplings teeth, with the receiving a spatial teeth geometry and ensuring required physical- mechanical properties of them, is presented. For implementation of this method, the scheme of the device and the special tool is developed, which allows to fair blanking of spatially modified teeth. The design procedure a teeth tool’s geometric parameters of the line addendum modification are offered.

scholarly journals Microstructure, Mechanical Properties, and Thermal Stability of Carbon-Free High Speed Tool Steel Strengthened by Intermetallics Compared to Vanadis 60 Steel Strengthened by Carbides

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1901
Author(s):  
Alena Michalcová ◽  
Vojtěch Pečinka ◽  
Zdeněk Kačenka ◽  
Jan Šerák ◽  
Jiří Kubásek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tool Steel ◽  
High Speed ◽  
Intermetallic Phase ◽  
High Hardness ◽  
Thermal Exposure ◽  
Machining Process ◽  
Material Utilization ◽  
Thermal Stability Of

High speed tool steels are materials that exhibit superior mechanical properties (e.g., high hardness). They should also be resistant to thermal exposure to maintain high hardness during the machining process. In this paper, a C-free tool steel formed of Fe matrix and a Mo6Co7 intermetallic phase was studied. This steel was compared to the well-known Vanadis 60 steel containing Fe matrix and carbides. Microstructures were investigated by scanning (SEM) and transmission (TEM) electron microscopy, and the mechanical properties and thermal stability of both materials were compared. It was proven that the strengthening in the Vanadis 60 steel was mainly caused by the carbides, while the C-free steel was strengthened by the Mo6Co7 phase. The hardness values of both materials were comparable in the utilization state (approx. 950 HV). The hardness of Vanadis 60 steel decreased after several minutes of annealing at 650 °C under the value that enables material utilization. The hardness value of the steel strengthened by the intermetallics also decreased but significantly slower. Based on these results, the main finding of this study is that the C-free steel exhibited much better thermal stability and may be utilized at higher temperatures for longer periods of time than Vanadis 60.

scholarly journals Influence of Build Orientation, Geometry and Artificial Saliva Aging on the Mechanical Properties of 3D Printed Poly(ε-caprolactone)

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3335
Author(s):  
Ana C. Pinho ◽  
Ana P. Piedade
Keyword(s):  
Mechanical Properties ◽  
Shape Factor ◽  
Artificial Saliva ◽  
Processing Parameters ◽  
Geometric Complexity ◽  
Critical Factors ◽  
Oral Environment ◽  
3D Printed ◽  
Regenerative Therapies ◽  
Functional Components

Additive manufacturing of polymers has evolved from rapid prototyping to the production of functional components/parts with applications in distinct areas, ranging from health to aeronautics. The possibility of producing complex customized geometries with less environmental impact is one of the critical factors that leveraged the exponential growth of this processing technology. Among the several processing parameters that influence the properties of the parts, the geometry (shape factor) is amid less reported. Considering the geometric complexity of the mouth, including the uniqueness of each teething, this study can contribute to a better understanding of the performance of polymeric devices used in the oral environment for preventive, restorative, and regenerative therapies. Thus, this work aims to evaluate 3D printed poly(ε-caprolactone) mechanical properties with different build orientations and geometries. Longitudinal and transversal toolpaths produced specimens with parallelepiped and tubular geometry. Moreover, as it is intended to develop devices for dentistry, the influence of artificial saliva on mechanical properties was determined. The research concluded that the best mechanical properties are obtained for parallelepiped geometry with a longitudinal impression and that aging in artificial saliva negatively influences all the mechanical properties evaluated in this study.

scholarly journals Fabricating Pyramidal Lattice Structures of 304 L Stainless Steel by Wire Arc Additive Manufacturing

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3482 ◽  
Author(s):  
Haorui Zhang ◽  
Junjin Huang ◽  
Changmeng Liu ◽  
Yongsheng Ma ◽  
Yafeng Han ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Large Scale ◽  
Lattice Structures ◽  
Layer Height ◽  
Superior Mechanical Properties ◽  
Material Utilization ◽  
Wire Arc Additive Manufacturing ◽  
Dendritic Austenite

Lattice structures have drawn considerable attention due to their superior mechanical properties. However, the existing fabrication methods for lattice structures require complex procedures, as they have low material utilization and lead to unreliable node connections, which greatly restricts their application. In this work, wire arc additive manufacturing is used to fabricate large-scale lattice structures efficiently, without any air holes between rods and panels. The principle and the process of fabricating the rods were analyzed systematically. The influence of the two most important parameters, including heat input and preset layer height, is disclosed. Through optical microscopy, the microstructure of the fabricated steel rods is found to consist of dendritic austenite and skeletal ferrite. The tensile strength of the rods can reach 603 MPa, and their elongation reaches 77%. These experimental results demonstrated the feasibility of fabricating lattice structures using wire arc additive manufacturing.

scholarly journals Engineering New Defective Phases of UiO Family Metal-Organic Frameworks with Water

2018 ◽  
Author(s):  
Francesca Firth ◽  
Matthew Cliffe ◽  
Diana Vulpe ◽  
Peyman Moghadam ◽  
David Fairen-jimenez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rational Design ◽  
Metal Organic Frameworks ◽  
Synthesis Temperature ◽  
Synthetic Control ◽  
Critical Factors ◽  
Defect Engineering ◽  
Metal Organic

As defects significantly affect the properties of metal-organic frameworks (MOFs)–from changing their mechanical properties to enhancing their catalytic ability–obtaining synthetic control over defects is essential to tuning the effects on the properties of the MOF. Previous work has shown that synthesis temperature and the identity and concentration of modulating acid are critical factors in determining the nature and distribution of defects in the UiO family of MOFs. In this paper we demonstrate that the amount of water in the reaction mixture in the synthesis of UiO family MOFs is an equally important factor, as it controls the phase which forms for both UiO-67(Hf)<br>and UiO-66(Hf) (F4BDC). We use this new understanding of the importance of water to develop a new route to the stable defect-ordered <b>hcp</b> UiO-66(Hf) phase, demonstrating the effectiveness of this method of defect-engineering in the rational design of MOFs. The insights provided by this<br>investigation open up the possibility of harnessing defects to produce new phases and dimensionalities of other MOFs, including nanosheets, for a variety of applications such as MOF-based membranes.

scholarly journals IMPROVEMENTS IN MODELLING RUBBLE-MOUND BREAKWATERS

1982 ◽  
Vol 1 (18) ◽  
pp. 122 ◽  
Author(s):  
G.W. Timco ◽  
E.P.D. Mansard
Keyword(s):  
Mechanical Properties ◽  
Design Procedure ◽  
Physical Modelling ◽  
Test Site ◽  
Model Tests ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Physical modelling is a technique which is commonly used in the design procedure of rubble-mound breakwaters. For reliable results it is necessary that the model tests accurately represent the prototype situation. In this paper, two significant improvements in modelling of breakwaters are presented. They are the generation of realistic sea states at the test site, and the simulation of the breakage of the armour units by using units which have mechanical properties properly scaled from the prototype units. These techniques have been used to study the recent breakwater failure at Riviere-au-Renard, Canada.

Deformation Behavior of Hollow Axles With Constant Hole Diameter by Three-Roll Skew Rolling

2020 ◽  
Author(s):  
Song Zhang ◽  
Xuedao Shu ◽  
Jitai Wang ◽  
Chang Xu
Keyword(s):  
Mechanical Properties ◽  
Rolling Direction ◽  
Rolling Process ◽  
Hole Diameter ◽  
Stress And Strain ◽  
Forming Process ◽  
Processing Efficiency ◽  
Forming Quality ◽  
Material Utilization ◽  
Skew Rolling

Abstract At present, hollow axles with constant hole diameter is mainly formed by turning thick-walled hollow tubes. This method of processing has low material utilization and processing efficiency. And heat treatment is required to improve the mechanical properties of hollow axles. To improve the material utilization and processing efficiency of hollow axles with constant hole diameter during the forming process, a new processing technique, three-roll skew rolling process, is proposed to form a hollow axles with constant hole diameter in this paper. The three-roll skew rolling process is a continuous plastic forming process, which has high material utilization and processing efficiency, and it can improve the mechanical properties of the rolled parts. Firstly, combining the working principle of three-roll skew rolling and the structural characteristics of hollow axles with constant hole diameter, the forming mechanism of hollow axles with constant hole diameter by three-roll skew rolling is described. Secondly, the finite element model of the hollow axles with constant hole diameter by three-roll skew rolling is established according to the dimensions of the hollow axles with constant hole diameter, the material characteristics of the hollow axles, and the stable rolling conditions of three-roll skew rolling. The process parameters of the hollow axles are also determined. Thirdly, according to each step position of the hollow axles, the forming process of the hollow axles with constant hole diameter by three-roll skew rolling is divided into 5 deformation stages. Lastly, the stress and strain field of each deformation stage of the hollow axles was analyzed. The results show that the dimensions of the hollow axles with constant hole diameter by three-roll skew rolling are very close to the designed dimensions, which indicates that the material utilization of the rolled hollow axles is very high. Along the rolling direction, the descending step of the hollow axle is easier to form than the ascending step, and the forming quality is also better. The surface metal of the rolled hollow axles flows faster than the internal metal. Areas with large stress and strain are mainly concentrated at both ends of the rolled hollow axles. And the magnitude of stress and strain gradually decrease from the surface to the center. The hollow axles with constant hole diameter by three-roll skew rolling has a good forming quality and high forming efficiency. The hollow axles with constant hole diameter is formed by three-roll skew rolling process, which has broad application prospects.

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