Probabilistic Safety Pin Coupling Failure Analysis to Explore

2015 ◽  
Vol 713-715 ◽  
pp. 114-117
Author(s):  
Shi Juan Wang
Keyword(s):  
Coupling Strength ◽  
Material Properties ◽  
Design Principle ◽  
Random Variable ◽  
Dispersion Characteristics ◽  
Probabilistic Design ◽  
Technical Requirements ◽  
Variable Limit ◽  
Size Dispersion ◽  
Safety Pin

Material properties and geometry of the safety coupling of the safety pin has a random uncertainty. Limit torque passed by coupling is a random variable. Limit torque variation within the interval Tmax and Tmin Reduced Mechanical Propertiematerial of material and the size dispersion characteristics in the design of the safety pin is a question that can be considered in the design principle of probability. It can make the technical requirements of safety and limit the scope of changes in the coupling strength of the material limits. Probabilistic design principles proposed design safety couplings used safety pin number

On Probabilistic Design

1974 ◽  
Vol 96 (4) ◽  
pp. 1291-1295 ◽  
Author(s):  
K. V. Bury
Keyword(s):  
Design Process ◽  
Safety Factor ◽  
Material Properties ◽  
Design Problem ◽  
Probabilistic Approach ◽  
Random Variable ◽  
Simple Design ◽  
Probabilistic Design ◽  
Extreme Value Model ◽  
Value Model

The probabilistic approach to design is developed and contrasted with the conventional safety factor approach. A careful interpretation of random variable design inputs is given, leading to a statistical extreme-value model of loads. In addition to the “reliability” concept, the concept of “mission length” is explicitly introduced to the design process. A simple design problem, involving random variable loads and constant material properties, is solved and illustrated. Possible extensions of this design problem, and their likely difficulties, are indicated.

Influence of parameters inhomogeneity on the existence of chimera states in a ring of nonlocally coupled maps

2021 ◽  
Vol 29 (6) ◽  
pp. 943-952
Author(s):  
Vasiliy Nechaev ◽  
◽  
Elena Rybalova ◽  
Galina Strelkova ◽  
◽  
...  
Keyword(s):  
Coupling Strength ◽  
Noise Intensity ◽  
Initial Conditions ◽  
Random Variable ◽  
Inhomogeneous Distribution ◽  
Control Parameters ◽  
Chimera States ◽  
Intensity Parameters ◽  
Different Characteristics ◽  
Ring Elements

The aim of the research is to study the influence of inhomogeneity in a control parameter of all partial elements in a ring of nonlocally coupled chaotic maps on the possibility of observing chimera states in the system and to compare the changes in regions of chimera realization using different methods of introducing the inhomogeneity. Methods. In this paper, snapshots of the system dynamics are constructed for various values of the parameters, as well as spatial distributions of cross-correlation coefficient values, which enable us to determine the regime observed in the system for these parameters. To improve the accuracy of the obtained results, the numerical studies are carried out for fifty different realizations of initial conditions of the ring elements. Results. It is shown that a fixed inhomogeneous distribution of the control parameters with increasing noise intensity leads to an increase in the range of the coupling strength where chimera states are observed. With this, the boundary lying in the region of strong coupling changes more significantly as compared with the case of weak coupling strength. The opposite effect is provided when the control parameters are permanently affected by noise. In this case increasing the noise intensity leads to a decrease in the interval of existence of chimera states. Additionally, the nature of the random variable distribution (normal or uniform one) does not strongly influence the observed changes in the ring dynamics. The regions of existence of chimera states are constructed in the plane of «coupling strength – noise intensity» parameters. Conclusion. We have studied how the region of existence of chimeras changes when the coupling strength between the ring elements is varied and when different characteristics of the inhomogeneous distribution of the control parameters are used. It has been shown that in order to increase the region of observing chimera states, the control parameters of the elements must be distributed inhomogeneously over the entire ensemble. To reduce this region, a constant noise effect on the control parameters should be used.

Investigation of Biotransport in a Tumor With Uncertain Material Properties Using a Nonintrusive Spectral Uncertainty Quantification Method

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Alen Alexanderian ◽  
Liang Zhu ◽  
Maher Salloum ◽  
Ronghui Ma ◽  
Meilin Yu
Keyword(s):  
Uncertainty Quantification ◽  
Material Properties ◽  
Statistical Models ◽  
Gaussian Random Field ◽  
Concentration Field ◽  
Random Variable ◽  
Spectral Projection ◽  
Velocity Fields ◽  
Efficient Computation ◽  
Uncertain Material Properties

In this study, statistical models are developed for modeling uncertain heterogeneous permeability and porosity in tumors, and the resulting uncertainties in pressure and velocity fields during an intratumoral injection are quantified using a nonintrusive spectral uncertainty quantification (UQ) method. Specifically, the uncertain permeability is modeled as a log-Gaussian random field, represented using a truncated Karhunen–Lòeve (KL) expansion, and the uncertain porosity is modeled as a log-normal random variable. The efficacy of the developed statistical models is validated by simulating the concentration fields with permeability and porosity of different uncertainty levels. The irregularity in the concentration field bears reasonable visual agreement with that in MicroCT images from experiments. The pressure and velocity fields are represented using polynomial chaos (PC) expansions to enable efficient computation of their statistical properties. The coefficients in the PC expansion are computed using a nonintrusive spectral projection method with the Smolyak sparse quadrature. The developed UQ approach is then used to quantify the uncertainties in the random pressure and velocity fields. A global sensitivity analysis is also performed to assess the contribution of individual KL modes of the log-permeability field to the total variance of the pressure field. It is demonstrated that the developed UQ approach can effectively quantify the flow uncertainties induced by uncertain material properties of the tumor.

A Probabilistic Approach for Determining the Component’s Dimension Under Fatigue Loadings

2009 ◽  
Author(s):  
Xiaobin Le ◽  
Jahan Rasty
Keyword(s):  
Fatigue Test ◽  
Test Data ◽  
Probabilistic Approach ◽  
Random Variables ◽  
Random Variable ◽  
Design Equation ◽  
Probabilistic Design ◽  
Material Fatigue ◽  
Stress Levels ◽  
Design Scenario

Due to inherent scatters in fatigue test data, the P-S-N curves are normally used to describe material fatigue behaviors. For probabilistic component’s design under fatigue loadings, the component’s dimension should be treated as a random variable because every dimension is certainly with a dimension tolerance. In this design scenario, it is difficult to determine the component’s dimension under fatigue loadings by using the P-S-N curves because stress levels are unknown and random variables. In this paper, a probabilistic approach is presented to build a generic probabilistic design equation which is governed by random variables related to material fatigue behaviors, component conditions and fatigue loadings. The generic probabilistic design equation can be used to determine component’s dimension with a given reliability. One example is presented for explaining the approach in details.

Integrated Multiscale Robust Design Considering Microstructure Evolution and Material Properties in the Hot Rolling Process

2014 ◽  
Author(s):  
Chung-Hyun Goh ◽  
Salman Ahmed ◽  
Adam P. Dachowicz ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Robust Design ◽  
Microstructure Evolution ◽  
Hot Rolling ◽  
Material Properties ◽  
Prediction Models ◽  
Solution Space ◽  
Rolling Process ◽  
Roll Pass ◽  
Technical Requirements ◽  
Property Performance

A transmission gear is generally produced by a sequence of several processes from steelmaking to final machining and surface treatment. The intermediate processes such as hot rolling induce microstructure evolution and phase transformation which play a significant role in determining the mechanical properties and fatigue strength of gears. Therefore, these intermediate processes should be carefully considered in determining the performance and properties of the end product. In this paper, an integrated multiscale robust design approach using the Inductive Design Exploration Method (IDEM) is implemented to improve robustness in the presence of uncertainty by exploring the solution space in order to find feasible solutions to satisfy technical requirements and/or customer aspirations. Four pass roll design with oval and round grooves is used to simulate the hot bar rolling process. The microstructure evolution, flow stress, and wear prediction models are implemented in the analysis model to account for the process-structure relationship in each roll pass. Surrogate models for some parameters such as ultimate tensile strength are then developed based on the analysis results. Using the relationship of processing-structure-property-performance, the integrated realization of engineered materials and products (IREMP) can be accomplished over multiple length scales. In IDEM, the range of the property-performance relationship is first evaluated by the requirements for the end product. Subsequently, the austenite and ferrite grain sizes and material properties are inductively determined by exploring the design space. Consequently roll pass design including the rolling conditions and the microstructure of billets are customized by the exploration of design variables based on IDEM.

Use in Probabilistic Design of the Maximum Entrophy Distribution Based on Ranked Data

1980 ◽  
Vol 102 (3) ◽  
pp. 460-468
Author(s):  
J. N. Siddall ◽  
Ali Badawy
Keyword(s):  
Probability Distribution ◽  
Maximum Entropy ◽  
Probability Distributions ◽  
Maximum Entropy Principle ◽  
Random Variable ◽  
Probabilistic Design ◽  
Entropy Principle ◽  
Almost All ◽  
New Distribution

A new algorithm using the maximum entropy principle is introduced to estimate the probability distribution of a random variable, using directly a ranked sample. It is demonstrated that almost all of the analytical probability distributions can be approximated by the new algorithm. A comparison is made between existing methods and the new algorithm; and examples are given of fitting the new distribution to an actual ranked sample.

scholarly journals Aging concrete structures: a review of mechanics and concepts

2018 ◽  
Vol 69 (3) ◽  
pp. 175-199 ◽  
Author(s):  
Roman Wan-Wendner
Keyword(s):  
Service Life ◽  
Bearing Capacity ◽  
Material Properties ◽  
Review Paper ◽  
Concrete Structures ◽  
Time Dependent ◽  
Efficient Management ◽  
Technical Requirements ◽  
Cost Efficient

Summary The safe and cost-efficient management of our built infrastructure is a challenging task considering the expected service life of at least 50 years. In spite of time-dependent changes in material properties, deterioration processes and changing demand by society, the structures need to satisfy many technical requirements related to serviceability, durability, sustainability and bearing capacity. This review paper summarizes the challenges associated with the safe design and maintenance of aging concrete structures and gives an overview of some concepts and approaches that are being developed to address these challenges.

scholarly journals Estimation of the Reliability of Automatic Axial-balancing Devices for Multistage Centrifugal Pumps

2018 ◽  
Vol 63 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Ivan Pavlenko ◽  
Justyna Trojanowska ◽  
Oleksandr Gusak ◽  
Vitalii Ivanov ◽  
Jan Pitel ◽  
...  
Keyword(s):  
Material Properties ◽  
Operating Parameters ◽  
Probabilistic Design ◽  
Centrifugal Pumps ◽  
New Approach ◽  
Dynamic Reliability ◽  
Multi Stage ◽  
Empirical Coefficients ◽  
Important Nodes ◽  
Permanent Increase

The permanent increase of operating parameters of modern multistage centrifugal pumps requires more precise modelling for estimation their dynamic reliability and needs to develop new approach and methodology for the related calculations. It is necessary to change the approach assuming empirical coefficients to another one based on the probabilistic design for analysis of reliability for pumps and their nodes. In this case, the probabilistic parameters of the design features and fluid flow are significant for the calculation (e. g. geometry of gap seals, boundary conditions, material properties) and should be considered. The automatic axial-balancing device of the rotor is one of the most important nodes of multi-stage centrifugal pumps. It operates as the balancing disc for the axial force up to 1 MN. This paper presents the methodology for the numerical calculation of the balancing disc and its influence on the reliability of multistage centrifugal pumps. The proposed approach is based on the criterion of the permissible amplitudes of axial oscillations of the rotor with the automatic axial-balancing device considering probabilistic origin of main geometrical, hydromechanical and operating parameters.

scholarly journals Hemp-lime composite for buildings insulation: material properties and regulatory framework

2019 ◽  
Vol 4 (1) ◽  
pp. 48 ◽  
Author(s):  
Rosa Agliata ◽  
Simone Gianoglio ◽  
Luigi Mollo
Keyword(s):  
Material Properties ◽  
Construction Materials ◽  
Regulatory Framework ◽  
Insulation Material ◽  
Building Envelopes ◽  
Technical Requirements ◽  
Materials Research ◽  
New Construction ◽  
Increasing Demand ◽  
Indoor Comfort

The increasing demand for indoor comfort in housing sector, together with the development of environmental awareness by people and societies, is leading to a rising need of new construction materials. Research and industries are then developing materials capable of meeting environmental and technical requirements: made from renewable sources; based on natural compounds to ensure healthy indoor environment and safe disposal; having good insulation properties, especially for energy saving. A material showing these features is the hemp-lime biocomposite, a natural-based mixture made of a lime binder matrix and shives aggregate, in different proportions. This paper wants to present an overview of the most interesting material properties for the building sector and a brief regulatory framework, in order to highlight the advantages that the use of this composite for building envelopes and internal partitions may provide.

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