Resonance failure sensitivity analysis of straight-tapered assembled pipes conveying nonuniform axial fluid by active learning Kriging method

2019 ◽  
Vol 15 (5) ◽  
pp. 975-989
Author(s):  
Yuzhen Zhao ◽  
Wei Liu ◽  
Qing Guo ◽  
Zijun Zhang
Keyword(s):  
Sensitivity Analysis ◽  
Active Learning ◽  
Natural Frequency ◽  
Critical Velocity ◽  
Failure Probability ◽  
Motion Equation ◽  
Content Type ◽  
Nonuniform Fluid ◽  
Importance Ranking ◽  
Uniform Fluid

Purpose The purpose of this paper is to study the resonance failure sensitivity analysis of straight-tapered assembled pipe conveying nonuniform axial fluid by an active learning Kriging (ALK) method. Design/methodology/approach In this study, first, the motion equation of straight-tapered assembled pipe conveying nonuniform fluid is built. Second, the Galerkin method is used for calculating the natural frequency of assembled pipe conveying nonuniform fluid. Third, the ALK method based on expected risk function (ERF) is used to calculate the resonance failure probability and moment independent global sensitivity analysis. Findings The findings of this paper highlight that the eigenfrequency and critical velocity of uniform fluid-conveying pipe are less than the reality and the error is biggest in first-order natural frequency. The importance ranking of input variables affecting the resonance failure can be obtained. The importance ranking is different for a different velocity and mode number. By reducing the uncertainty of variables with a high index, the resonance failure probability can be reduced maximally. Research limitations/implications There are no experiments on the eigenfrequency and critical velocity. There is no experiments about natural frequency and critical velocity of straight tapered assembled pipe to verify the theory in this paper. Originality/value The originality of this paper lies as follows: the motion equation of straight-tapered pipe conveying nonuniform fluid is first obtained. The eigenfrequency of nonuniform fluid and uniform fluid inside the assembled pipe are compared. The resonance reliability analysis of straight-tapered assembled pipe is first proposed. From the results, it is observed that the resonance failure probability can be reduced efficiently.

scholarly journals Resonance risk and global sensitivity analysis of a straight–curved combination pipe based on active learning Kriging model

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983835
Author(s):  
Yuzhen Zhao ◽  
Yongshou Liu ◽  
Qing Guo ◽  
Tao Han ◽  
Baohui Li
Keyword(s):  
Sensitivity Analysis ◽  
Active Learning ◽  
Coordinate System ◽  
Failure Probability ◽  
Global Sensitivity Analysis ◽  
Dynamic Stiffness ◽  
Kriging Model ◽  
Global Sensitivity ◽  
Pipes Conveying Fluid ◽  
Conveying Fluid

The resonance failure of straight–curved combination pipes conveying fluid which are widely used in engineering is becoming a serious issue. But there are only few studies available on the resonance failure of combination pipes. The resonance failure probability and global sensitivity analysis of straight–curved combination pipes conveying fluid are studied by the active learning Kriging method proposed in this article. Based on the Euler–Bernoulli beam theory, the dynamic stiffness matrices of straight and curved pipes are derived in the local coordinate system, respectively. Then the dynamic stiffness matrix and characteristic equation of a straight–curved combination pipe conveying fluid are assembled under a global coordinate system. The natural frequency is calculated based on the characteristic equation. A resonance failure performance function is established based on the resonance failure mechanism and relative criterions. The active learning Kriging model based on expected risk function is introduced for calculating the resonance failure probability and moment-independent global sensitivity analysis index. The importance rankings of input variables are obtained with different velocities. According to the results, it is shown that the method proposed in this article provides a lot of guidance for resonance reliability analysis and anti-resonance design in combination pipes conveying fluid.

Approximate Sensitivity Analysis of Structure System Based on Failure Probability under Epistemic and Aleatory Uncertainties

2011 ◽  
Vol 243-249 ◽  
pp. 5674-5679
Author(s):  
Pan Wang ◽  
Zhen Zhou Lu ◽  
Qi Wang
Keyword(s):  
Sensitivity Analysis ◽  
Failure Probability ◽  
Universal Method ◽  
Correlation Ratio ◽  
Structure System ◽  
Sensitivity Indices ◽  
Importance Ranking ◽  
Two Indices ◽  
Uncertainty Parameters ◽  
The Impact

For analyzing effect of epistemic and aleatory uncertainties on failure probability of structure system involving uncertainties, two sensitivity indices, i.e. Correlation Coefficient and Correlation Ratio on the failure probability are defined, the universal method and approximate method for solving two indices are investigated and the corresponding precision and efficiency are discussed. By analyzing the two indices on the failure probability, the importance ranking of the uncertainty impacting on the failure probability can be quantified, on which the information for controlling the failure probability can be obtained effectively. After the detailing implementations for two sensitivity indices, several numerical and engineering samples are used to validate the precision and efficiency of two methods, and the law of the impact of the uncertainty parameters on the sensitivity result is obtained as well.

A dynamic model of laminated material extrusion additive manufacturing plate with the property of orthogonal anisotropy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shijie Jiang ◽  
Mingyu Sun ◽  
Yang Zhan ◽  
Hui Li ◽  
Wei Sun
Keyword(s):  
Sensitivity Analysis ◽  
Additive Manufacturing ◽  
Dynamic Model ◽  
Natural Frequency ◽  
Dynamic Behavior ◽  
Theoretical Basis ◽  
Resonant Response ◽  
Content Type ◽  
Set Up ◽  
Orthogonal Anisotropy

Purpose The purpose of this study is to set up a dynamic model of material extrusion (ME) additive manufacturing plates for the prediction of their dynamic behavior (i.e. dynamic inherent characteristic, resonant response and damping) and also carry out its experimental validation and sensitivity analysis. Design/methodology/approach Based on the classical laminated plate theory, a dynamic model is established using the orthogonal polynomials method, taking into account the effect of lamination and orthogonal anisotropy. The dynamic inherent characteristics of the ME plate are worked out by Ritz method. The frequency-domain dynamic equations are then derived to solve the plates’ resonant responses, with which the damping ratio is figured out according to the half-power bandwidth method. Subsequently, a series of experimental tests are performed on the ME samples to obtain the measured data. Findings It is shown that the predictions and measurements in terms of dynamic behavior are in good agreement, validating the accuracy of the developed model. In addition, sensitivity analysis shows that increasing the elastic modulus or Poisson’s ratio will increase the corresponding natural frequency of the ME plate but decrease the resonant response. When the density is increased, both the natural frequency and resonant response will be decreased. Research limitations/implications Future research can be focused on using the proposed model to investigate the effect of processing parameters on the ME parts’ dynamic behavior. Practical implications This study shows theoretical basis and technical insight into improving the forming quality and reliability of the ME parts. Originality/value A novel reliable dynamic model is set up to provide theoretical basis and principle to reveal the physical phenomena and mechanism of ME parts.

scholarly journals Estimating probability of fatigue failure of steel structures

2020 ◽  
Vol 23 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Z. Kala
Keyword(s):  
Sensitivity Analysis ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Fatigue Crack ◽  
Failure Probability ◽  
Bending Moment ◽  
Steel Structures ◽  
Fatigue Properties ◽  
Linear Fracture ◽  
Importance Ranking

The article deals with the analysis of failure probability of the effect of random factors in uencing fatigue crack propagation in a steel element under bending moment. The theoretical model of fatigue crack progression is based on linear fracture mechanics. When determining the required degree of failure probability, it is possible to specify the time of the first inspection of the construction, which will focus on the fatigue damage. Using a conditional probability, subsequent inspection times are specified. The failure probability is examined using a fairly new sensitivity analysis subordinated to a contrast. The importance ranking of the input random variables to the failure probability is investigated. Fatigue properties of steel are taken from recent experimental research. Numerical results are obtained using the Monte Carlo simulation.

scholarly journals Dynamics of axially functionally graded conical pipes conveying fluid

2021 ◽  
Vol 37 ◽  
pp. 318-326
Author(s):  
Yuzhen Zhao ◽  
Dike Hu ◽  
Song Wu ◽  
Xinjun Long ◽  
Yongshou Liu
Keyword(s):  
Natural Frequency ◽  
Critical Velocity ◽  
Volume Fraction ◽  
Differential Quadrature Method ◽  
Reduction Factor ◽  
Functionally Graded ◽  
Function Type ◽  
Pipes Conveying Fluid ◽  
Volume Fraction Function ◽  
Conveying Fluid

Abstract In this paper, the dynamics of axially functionally graded (AFG) conical pipes conveying fluid are analyzed. The materials are distributed along the conical pipe axis as a volume fraction function. Either the elastic modulus or the density of the AFG conical pipe is assumed to vary from the inlet to the outlet. The governing equation of the AFG conical pipe is derived using the Hamiltonian principle and solved by the differential quadrature method. The effects of the volume fraction index, volume fraction function type and reduction factor on the natural frequency and critical velocity are analyzed. It is found that for a power function volume fraction type, the natural frequency and critical velocity increase with increasing volume fraction index and clearly increase when the volume fraction index is within the range (0, 10). For an exponential function volume fraction type, the natural frequency and critical velocity change rapidly within the range (−10, 10), besides the above range the relationship between the natural frequency, critical velocity and volume fraction index is approximate of little change. The natural frequency and critical velocity decrease linearly with increasing reduction factor.

Investigation of Sensitivity Effect Based on Mass and Stiffness Modification in Automobile Crankshaft

2015 ◽  
Vol 752-753 ◽  
pp. 839-844
Author(s):  
R.M.S. Zetty ◽  
B.A. Aminudin ◽  
L.M. Aung ◽  
M.K. Khalid ◽  
H.M.Y. Norfazrina ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
Differential Analysis ◽  
Partial Differential ◽  
Mechanical Parts ◽  
Stiffness Reduction ◽  
Experiment And Simulation ◽  
Good Agreement

A modeling through sensitivity analysis is one of the promising methods to investigate the dynamic characteristics of complex mechanical parts. This study aimed to investigate the effect of sensitivity based on mass and stiffness modification in automobile crankshaft as a function of natural frequency. Verification for the crankshaft model that is used in the experiment and simulation was done and both results showed good agreement and small errors percentage. The modification was also done by reducing the different percentage of crankshaft’s mass and stiffness. Partial differential analysis was used in the sensitivity analysis in order to figure out the natural frequency after every set of modification. According to the results, we also found that there were changes of sensitivity value by changes in mass value but the stiffness value remains unchanged. However, there is no significant effect of stiffness reduction on vibration was found in this research.

Optimum design of composite structures with ply drop-offs using response surface methodology

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Camila Aparecida Diniz ◽  
Yohan Méndez ◽  
Fabrício Alves de Almeida ◽  
Sebastião Simões da Cunha Jr ◽  
G.F. Gomes
Keyword(s):  
Response Surface Methodology ◽  
Natural Frequency ◽  
Design Variable ◽  
Composite Structures ◽  
Laminate Plate ◽  
Longitudinal Direction ◽  
Stacking Sequence ◽  
Direct Influence ◽  
Optimization Strategy ◽  
Content Type

Purpose Many studies only take into account the ply stacking sequence as the design variable to determine the optimal ply drop-off location; however, it is necessary to optimize other parameters that have a direct influence on the ply drop-off site such as which plies should be dropped and in which longitudinal direction. That way, the purpose of this study is to find the most significant design variables relative to the drop-off location considering the transversal and longitudinal positions, seeking to achieve the optimal combination of ply drop-off locations that provides excellent performance for the laminate plate. Design/methodology/approach This study aims to determine the optimal drop-off location in a laminate plate using the finite element method and an approach statistical with design of experiments (DOE). Findings The optimization strategy using DOE revealed to be satisfactory for analyzing laminate structures with ply drop-offs, demonstrating that not all design factors influence the response variability. The failure criterion response variable revealed a poor fit, with an adjusted coefficient of determination lower than 60%, thus demonstrating that the response did not vary with the ply drop-off location. Already the strain and natural frequency response variables presented high significance. Finally, the optimization strategy revealed that the optimal drop-off location that minimizes the strain and maximizes the natural frequency is the ply drop-off located of the end plate. Originality/value It was also noted that many researchers prefer evolutionary algorithms for optimizing composite structures with ply drop-offs, being scarce to the literature studies involving optimization strategies using response surface methodology. In addition, many studies only take into account the ply stacking sequence as the design variable to determine the optimal ply drop-off location; however, in this study, the authors investigated other important parameters that have direct influence on the ply drop-off site such as which plies should be dropped and in which longitudinal direction.

Dynamic supplier selection approach for mining equipment company

2019 ◽  
Vol 14 (1) ◽  
pp. 77-105 ◽  
Author(s):  
Md. Tanweer Ahmad ◽  
Sandeep Mondal
Keyword(s):  
Sensitivity Analysis ◽  
Supplier Selection ◽  
Business Environment ◽  
Spare Parts ◽  
Mixed Integer ◽  
Optimal Order ◽  
Mining Equipment ◽  
Order Allocation ◽  
Managerial Implication ◽  
Content Type

PurposeThis paper aims to address the supplier selection (SS) problem under dynamic business environments to optimize the procurement cost of spare-parts in the context of a mining equipment company (MEC). Practically, involved parameters’ value does not remain constant as planning periods due to fluctuation in the demand and their market dynamics. Therefore, dynamicity in the parameter is considered as an important factor when a company forms a responsive chain through most eligible suppliers with respect to planning periods. This area of study may be considered for their complexities to the approaches toward order-allocations with bi-products of unused and repair spare-parts.Design/methodology/approachAn integrated methodology of analytic hierarchy process (AHP) and mixed-integer non-linear programming (MILP) is implemented in the two stages during each planning periods. In the first stage, AHP is used to obtain the relative weights with respect to each spare-parts of each criterion and based on that, the ranking is evaluated in accordance with case considered. And in the second stage, MILP is formulated to find the allocations of each spare-part with two distinct approaches through Model-1 and Model-2 separately. Moreover, Model-1 and Model-2 are outlined based on the ranking and efficient parameters-value under cost, limited capacities, quality level and delay lead time respectively.FindingsThe ranking and their optimal order-allocation of potential suppliers are obtained during consecutive planning periods for both unused and repair spare-parts. Subsequently, sensitivity analysis is conducted to deduce the key nuggets with the comparison of Model-1 and Model-2 in the changing of capacity, demand and cost per spare-parts. From this analysis, it is found that suppliers who have optimal parameter settings would be better for order-allocations than ranking during the changing planning period.Practical implicationsThis paper points out the situation-specific approach for SS problem for a mining industry which often faces disruptive supplying environments. The managerial implication between ranking and parameters are highlighted through Model-1 and Model-2 by sensitivity analysis.Originality/valueIt provides useful directions for managers who are involved in the procurement of spare-parts in the mining environment. For this, suppliers are selected for order-allocation by using Model-1 and Model-2 in the dynamic business environment. The solvability of the model is presented using LINGO 17. Furthermore, the case company selected in this study can be extended to other sectors.

Optimal design of a parallel robotic gripper using enhanced multi-objective ant lion optimizer with a sensitivity analysis approach

2020 ◽  
Vol 40 (5) ◽  
pp. 703-721
Author(s):  
Golak Bihari Mahanta ◽  
Deepak BBVL ◽  
Bibhuti B. Biswal ◽  
Amruta Rout
Keyword(s):  
Sensitivity Analysis ◽  
Distribution Function ◽  
Design Parameters ◽  
Objective Functions ◽  
Content Type ◽  
Multi Objective ◽  
The Past ◽  
Design Variables ◽  
Pick And Place ◽  
Ant Lion

Purpose From the past few decades, parallel grippers are used successfully in the automation industries for performing various pick and place jobs due to their simple design, reliable nature and its economic feasibility. So, the purpose of this paperis to design a suitable gripper with appropriate design parameters for better performance in the robotic production systems. Design/methodology/approach In this paper, an enhanced multi-objective ant lion algorithm is introduced to find the optimal geometric and design variables of a parallel gripper. The considered robotic gripper systems are evaluated by considering three objective functions while satisfying eight constraint equations. The beta distribution function is introduced for generating the initial random number at the initialization phase of the proposed algorithm as a replacement of uniform distribution function. A local search algorithm, namely, achievement scalarizing function with multi-criteria decision-making technique and beta distribution are used to enhance the existing optimizer to evaluate the optimal gripper design problem. In this study, the newly proposed enhanced optimizer to obtain the optimum design condition of the design variables is called enhanced multi-objective ant lion optimizer. Findings This study aims to obtain optimal design parameters of the parallel gripper with the help of the developed algorithms. The acquired results are investigated with the past research paper conducted in that field for comparison. It is observed that the suggested method to get the best gripper arrangement and variables of the parallel gripper mechanism outperform its counterparts. The effects of the design variables are needed to be studied for a better design approach concerning the objective functions, which is achieved by sensitivity analysis. Practical implications The developed gripper is feasible to use in the assembly operation, as well as in other pick and place operations in different industries. Originality/value In this study, the problem to find the optimum design parameter (i.e. geometric parameters such as length of the link and parallel gripper joint angles) is addressed as a multi-objective optimization. The obtained results from the execution of the algorithm are evaluated using the performance indicator algorithm and a sensitivity analysis is introduced to validate the effects of the design variables. The obtained optimal parameters are used to develop a gripper prototype, which will be used for the assembly process.

scholarly journals Constructing constructivism in management accounting education: reflections from a teaching cycle with innovative learning elements

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kelum Jayasinghe
Keyword(s):  
Active Learning ◽  
Qualitative Methods ◽  
Management Accounting ◽  
Accounting Education ◽  
Constructivist Teaching ◽  
Learning Approaches ◽  
Content Type ◽  
Radical Constructivist ◽  
Innovative Learning ◽  
Management Accounting Education

Purpose This study aims to address the possibility of integrating some elements of the “radical constructivist” approach to management accounting teaching. It answers the following two questions: to what extent should management accounting educators construct a “radical constructivist” foundation to guide active learning? Then, in which ways can management accounting educators use qualitative methods to facilitate “radical constructivist” education? Design/methodology/approach The study uses a teaching cycle that implements innovative learning elements, e.g. learning from ordinary people, designed following the principles of “radical constructivism”, to engage students with “externalities” at the centre of their knowledge construction. It adopts an ethnographic approach comprising interviews and participant observation for the data collection, followed by the application of qualitative content and narrative analysis of the data. Findings The study findings and reflections illustrate that the majority of students respond positively to radical constructivist learning if the educators can develop an innovative problem-solving and authentic environment that is close to their real lives. The radical constructivist teaching cycle discussed in this study has challenged the mindsets of the management accounting students as it altered the traditional objectivist academic learning approaches that students were familiar with. Its use of qualitative methods facilitated active learning. Student feedback was sought as part of the qualitative design, which provided a constructive mechanism for the students and educators to learn and unlearn from their mistakes. This process enriched the understanding of learners (students) and educators of successful engagement in radical constructivist management accounting education and provides a base upon which to design future teaching cycles. Originality/value The paper provides proof of the ability of accounting educators, as change agents, to apply radical constructivist epistemology combined with multiple qualitative research methods by creating new constructive learning structures and cultures associated with innovative deep-learning tasks in management accounting education.

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