The Basis for Reliability-Based Mechanical Properties of Structural Aluminium Alloys

Adequate knowledge of mechanical properties and their statistical description is the basis for performing reliable verification of design methods and design of structures in general. The probabilistic design approach implemented in Eurocodes requires statistical data on all variables used in the design procedure. Although aluminium was introduced in structural Eurocodes more than four decades ago (ENV), the statistical database of mechanical properties is still inadequate. To provide a reliable statistical background, data collection was performed concerning aluminium products mainly found in the European market, within the last 20 years regarding certificates from the aluminium industry and 30 years regarding data from the research community. The collected data include aluminium alloy series 1xxx, 5xxx, 6xxx, and 7xxx, mainly extruded, and relevant mechanical properties such as 0.2% proof strength, ultimate strength, Young’s modulus, and Poisson’s ratio. They were fit to distributions, and relevant fractiles were determined, along with an analysis of nominal to characteristic and design value ratios. Variation of ratios obtained shows that that the majority of nominal values are economical and reliable. However, certain adjustments to nominal values are required to achieve a uniform reliability level in terms of the choice of alloy and temper.

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The Effect of Water Concentration in Ethyl Alcohol on the Environmentally Assisted Embrittlement of Austempered Ductile Irons

Metals ◽

10.3390/met11010094 ◽

2021 ◽

Vol 11 (1) ◽

pp. 94

Author(s):

Petar Janjatovic ◽

Olivera Eric Cekic ◽

Leposava Sidjanin ◽

Sebastian Balos ◽

Miroslav Dramicanin ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Cast Iron ◽

Ultimate Tensile Strength ◽

Ethyl Alcohol ◽

Water Concentration ◽

Different Types ◽

Influence Of Water ◽

Iron Material ◽

Proof Strength

Austempered ductile iron (ADI) is an advanced cast iron material that has a broad field of application and, among others, it is used in contact and for conveyance of fluids. However, it is noticed that in contact with some fluids, especially water, ADI material becomes brittle. The most significant decrease is established for the elongation. However, the influence of water and the cause of this phenomenon is still not fully understood. For that reason, in this paper, the influence of different water concentrations in ethyl alcohol on the mechanical properties of ADI materials was studied. The test was performed on two different types of ADI materials in 0.2, 4, 10, and 100 vol.% water concentration environments, and in dry condition. It was found that even the smallest concentration of water (0.2 vol.%) causes formation of the embrittled zone at fracture surface. However, not all mechanical properties were affected equally and not all water concentrations have been critical. The highest deterioration was established in the elongation, followed by the ultimate tensile strength, while the proof strength was affected least.

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Design Nomographs of Compression Helical Springs for Predetermined Reliability Levels

Journal of Mechanical Design ◽

10.1115/1.3254902 ◽

1981 ◽

Vol 103 (2) ◽

pp. 268-273

Author(s):

My Dao Thien ◽

M. Massoud

Keyword(s):

Probabilistic Approach ◽

Design Procedure ◽

Axial Loading ◽

Geometric Parameters ◽

Computer Algorithms ◽

Mean Values ◽

Helical Springs ◽

Reliability Level ◽

Classical Design ◽

Mission Success

This paper discusses a probabilistic approach for the design of Compression Closely Coiled Helical Springs subjected to periodic axial loading. The classical design procedure results in deterministic geometric parameters with tolerances normally chosen according to standards without due regard to their effects on the mission success as normally expressed by a reliability level. With the proposed design procedure, the engineer can specify nominal mean values for the geometric parameters and their tolerances according to a predetermined reliability level. Design nomographs are presented to help the engineer, in the early stages of design, to choose between many alternatives. Computer algorithms can easily be written to verify the final or optimum design.

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Statistical data on the mechanical properties and thickness of alloy steel plates

Metal Science and Heat Treatment ◽

10.1007/bf00647818 ◽

1969 ◽

Vol 10 (12) ◽

pp. 980-981

Author(s):

V. I. Vetrov ◽

A. A. Kuznetsov

Keyword(s):

Mechanical Properties ◽

Alloy Steel ◽

Statistical Data ◽

Steel Plates

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Estimates of Federal ownership of undiscovered oil and gas resources by province; statistical background data for U.S. Geological Survey Circular 860

Open-File Report ◽

10.3133/ofr82666b ◽

1982 ◽

Author(s):

K. L. Varnes ◽

G.L. Dolton

Keyword(s):

Oil And Gas ◽

Geological Survey ◽

Background Data ◽

Oil And Gas Resources ◽

Statistical Background

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.345-346.335 ◽

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.

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Effect of Sigma Phase in Co-29Cr-6Mo Alloy on Corrosion and Mechanical Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.26-28.777 ◽

2007 ◽

Vol 26-28 ◽

pp. 777-780 ◽

Cited By ~ 2

Author(s):

Shingo Kurosu ◽

Naoyuki Nomura ◽

Akihiko Chiba

Keyword(s):

Mechanical Properties ◽

Aging Time ◽

Inductively Coupled Plasma ◽

Sigma Phase ◽

Atomic Emission ◽

Area Fraction ◽

Plasma Atomic Emission ◽

Σ Phase ◽

Inductively Coupled ◽

Proof Strength

Effect of the sigma (σ) phase in Co-29Cr-6Mo alloy on corrosion and mechanical behavior has been investigated. The area fraction of the σ phase varies depending on the aging time at 1023 K. The area fraction of the sigma phase increases with increasing aging time and reaches 0.6 % after aging at 1023 K for 21.6 ks. Inductively coupled plasma atomic emission spectrometer (ICP-AES) analysis revealed the quantity of released Co ion shows almost the same values regardless of different area fraction of the σ phase. In addition, plastic elongation and 0.2% proof strength exhibit almost the same values, although the alloys have different area fraction of the σ phase. These results suggest that a small amount of the σ phase (<0.6%) hardly affect the corrosion and mechanical properties in the Co-29Cr-6Mo alloy.

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Criteria for Evaluating Bolt Head Design

Journal of Engineering for Industry ◽

10.1115/1.3439078 ◽

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.

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