Fast probabilistic design procedure for axially compressed composite cylinders

Current approaches to the design of structures are based on the concept of target probability of failure. This value is, however, often specified on the basis of comparative studies and past experience only. Moreover, the traditional probabilistic approach cannot properly consider gross errors and accidental situations, both of which are becoming more frequent causes of failure. This paper shows that it is useful to supplement a probabilistic design procedure by a risk analysis and assessment, which can take into account the consequences of all unfavourable events. It is anticipated that in the near future advanced engineering design will include criteria of acceptable risks in addition to the traditional probabilistic conditions.

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

Applied Sciences ◽

10.3390/app11104485 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4485

Author(s):

Davor Skejić ◽

Tihomir Dokšanović ◽

Ivan Čudina ◽

Federico M. Mazzolani

Keyword(s):

Mechanical Properties ◽

Statistical Data ◽

Design Procedure ◽

Probabilistic Design ◽

Reliability Level ◽

Adequate Knowledge ◽

Alloy Series ◽

Background Data ◽

Statistical Background ◽

Proof Strength

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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Application of Computational Mechanics to Tire Design—Yesterday, Today, and Tomorrow

Tire Science and Technology ◽

10.2346/1.3670034 ◽

2011 ◽

Vol 39 (4) ◽

pp. 223-244 ◽

Cited By ~ 16

Author(s):

Y. Nakajima

Keyword(s):

Finite Element ◽

New Technologies ◽

Computational Mechanics ◽

Design Procedure ◽

Side Wall ◽

Rolling Resistance ◽

Optimization Techniques ◽

Stress Strain ◽

Element Analysis ◽

Crown Shape

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.

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Issues on Design of Piled Raft Foundation

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v14i1.5905 ◽

2018 ◽

Vol 14 (1) ◽

pp. 6057-6061 ◽

Cited By ~ 1

Author(s):

Padmanaban M S ◽

J Sreerambabu

Keyword(s):

Contact Area ◽

Concrete Slab ◽

Design Procedure ◽

Bending Moment ◽

Foundation Design ◽

Detailed Review ◽

Piled Raft ◽

Piled Raft Foundation ◽

Raft Foundation ◽

Influencing Parameters

A piled raft foundation consists of a thick concrete slab reinforced with steel which covers the entire contact area of the structure, in which the raft is supported by a group of piles or a number of individual piles. Bending moment on raft, differential and average settlement, pile and raft geometries are the influencing parameters of the piled raft foundation system. In this paper, a detailed review has been carried out on the issues on the raft foundation design. Also, the existing design procedure was explained.

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