Optimization Based Approach to Automate Fatigue Durability Test Load Development

2007 ◽  
Author(s):  
Jaychandar Muthu ◽  
Brian Choi
Keyword(s):  
Fatigue Damage ◽  
Development Process ◽  
Failure Modes ◽  
Test Development ◽  
Optimization Algorithms ◽  
System Level ◽  
Underlying Structure ◽  
Test Load ◽  
Fatigue Durability ◽  
Loading Constraints

Loads for structural fatigue durability tests are often developed by considering only the load data and ignoring the structure and its failure modes. Typically, in these procedures, the load data is directly used with a fatigue damage calculation method to compute the most damaging loading direction and magnitude. These processes ignore the underlying structure and hence may not arrive at loading modes that are sensitive to the failure modes of the structure. The structure, with its failure modes, wield considerable influence on the test load selection and ought to be considered in the test development. FEA tools can be employed for this purpose. However, due to the iterative nature of the test development process and the repeated FEA analysis it entails, the development task can become tedious. Here, an optimization based approach to automate the test load development process is proposed. This methodology leverages optimization algorithms to arrive at the test load cycles with proper load phasing even when a large number of load channels are involved. This method permits linear or nonlinear FEA procedures with component or system level test setups. This method also allows for maximizing the fatigue damage at the primary ‘key life’ failure location. A range of loading constraints — from constraints based on durability loading histories to constraints due to testing rig limitations — may be applied. In this discussion, a unique approach to setup lab test development problems that are conducive to optimization algorithms is delineated. As a part of this process, a novel approach to set loading constraints by utilizing multidimensional scatter plots of the existing loading histories will also be shown. The effectiveness of well known optimization methods in searching and arriving at the test load cycles will be also highlighted.

scholarly journals Set Theoretical Variants of Optimization Algorithms for System Reliability-based Design of Truss Structures

2021 ◽  
Author(s):  
Ali Kaveh ◽  
Kiarash Biabani Hamedani ◽  
Mohammad Kamalinejad
Keyword(s):  
Design Optimization ◽  
System Reliability ◽  
Failure Modes ◽  
Optimization Problems ◽  
Optimization Algorithms ◽  
System Level ◽  
Truss Structures ◽  
Jaya Algorithm ◽  
Reliability Based Design Optimization ◽  
Reliability Based Design

In this paper, recently developed set theoretical variants of the teaching-learning-based optimization (TLBO) algorithm and the shuffled shepherd optimization algorithm (SSOA) are employed for system reliability-based design optimization (SRBDO) of truss structures. The set theoretical variants are designed based on a simple framework in which the population of candidate solutions is divided into some number of smaller well-arranged sub-populations. In addition, the framework is applied to the Jaya algorithm, leading to a set-theoretical variant of the Jaya algorithm. So far, most of the reliability-based design optimization studies have focused on the reliability of single structural members. This is due to the fact that the optimization problems with system reliability-based constraints are computationally expensive to solve. This is especially the case of statically redundant structures, where the number of failure modes is so high that it is impractical to identify all of them. System-level reliability analysis of truss structures is carried out by the branch and bound method by which the stochastically dominant failure paths are identified within a reasonable time. At last, three numerical examples, including size optimization of truss structures, are presented to illustrate the effectiveness of the proposed SRBDO approach. The results indicate the efficiency and applicability of the set theoretical optimization algorithms to solve the SRBDO problems of truss structures.

scholarly journals USING MODEL-BASED SYSTEMS ENGINEERING FOR NEED-BASED AND CONSISTENT SUPPORT OF THE DESIGN PROCESS

2021 ◽  
Vol 1 ◽  
pp. 3369-3378
Author(s):  
Stephan Husung ◽  
Christian Weber ◽  
Atif Mahboob ◽  
Sven Kleiner
Keyword(s):  
Systems Engineering ◽  
Development Process ◽  
Added Value ◽  
System Level ◽  
System Failure ◽  
Model Based ◽  
Continuous Use ◽  
Model Based Systems Engineering ◽  
Consistent Support ◽  
Modelling Approaches

AbstractModel-Based Systems Engineering (MBSE) is an efficient approach to support product development in order to meet today's challenges. The MBSE approach includes methods and, above all, modelling approaches of the technical system with the aim of continuous use in development. The objective of this paper is to use the potential of the MBSE models and to show the added value of such models on the system level when used as a single source. With this objective, this paper presents a three-step approach to systematically identify and apply meaningful modelling approaches within MBSE, based on the needs during the development process. Furthermore, an FMEA example is included in this paper to elaborate the use of MBSE in the system failure analysis.

Application of Failure Modes and Effects Analysis to Support Product In-Use Information Feedback

2009 ◽  
Author(s):  
Grant McSorley ◽  
Greg Huet ◽  
Stephen J. Culley ◽  
Clement Fortin
Keyword(s):  
Development Process ◽  
Failure Modes ◽  
Product Information ◽  
Product Structure ◽  
Design Stage ◽  
Information Feedback ◽  
Product Structures

Due to their increasing responsibility for the total lifecycle costs associated with their products, manufacturers are investing increasingly more efforts in their reduction. One way in which this can be achieved is through the elimination at the design stage of possible in-service issues. This can be supported through the feedback of product in-use information obtained from testing, prototyping and in-service lifecycle stages towards the earlier stages of the development process. In order to facilitate the feedback of this information to design, the idea of complimentary product structures is introduced. The relationships between these structures provide a link between product information across the various lifecycle stages. The similarities between the product structure and the FMEA structure are also examined. As the FMEA organizes its information on a component basis, it is suggested that it provides an adequate basis for the organization of the product in-use information in order to facilitate its association with the product structure. Based on these ideas, a full framework for the feedback and reuse of product in-use information is described.

Failure Analysis of Thinned Wall Elbows Under Excessive Seismic Loading

2002 ◽  
Author(s):  
Masaki Shiratori ◽  
Yoji Ochi ◽  
Izumi Nakamura ◽  
Akihito Otani
Keyword(s):  
Finite Element ◽  
Fatigue Damage ◽  
Failure Modes ◽  
Low Cycle Fatigue ◽  
Local Buckling ◽  
Seismic Loading ◽  
Cycle Fatigue ◽  
Finite Element Analyses ◽  
Residual Thickness ◽  
Limited Period

A series of finite element analyses has been carried out in order to investigate the failure behaviors of degraded bent pipes with local thinning against seismic loading. The sensitivity of such parameters as the residual thickness, locations and width of the local thinning to the failure modes such as ovaling and local buckling and to the low cycle fatigue damage has been studied. It has been found that this approach is useful to make a reasonable experimental plan, which has to be carried out under the condition of limited cost and limited period.

Introducing Knowledge-Based Engineering Into an Interconnected Product Development Process

1999 ◽  
Author(s):  
Daniel E. Whitney ◽  
Qi Dong ◽  
Jared Judson ◽  
Gregory Mascoli
Keyword(s):  
Development Process ◽  
Product Development Process ◽  
System Level ◽  
Knowledge Based ◽  
Design Structure ◽  
Engine Component ◽  
Level Information ◽  
Tightly Coupled ◽  
Knowledge Based Engineering ◽  
Knowledge Content

Abstract Recently, a large automobile company implemented a Knowledge-based Engineering (KBE) application to help design an engine component. While the KBE developers aimed to facilitate a single engineer’s ability to design this component using only the KBE application, it can be shown that in fact this component’s design is tightly coupled to that of several others. Can KBE handle situations like this? How common are they? To address these and other questions, Design Structure Matrix (DSM) models were made of this component at three levels: system interactions, assembly of the component, and individual parts. The size, row names, and internal entries of these matrices were compared to matrices constructed from several conventional written design guides and a flowchart of the KBE application. In each case, the DSM contained more rows or more matrix entries per row, especially at the system interaction level. Since the DSMs were constructed by interviewing experienced engineers, one implication is that while low-aggregation information may be documented, system level information at this company mostly resides in people’s heads. An informal measure of “knowledge content” based on the number of matrix entries per row was shown to be consistent with similar measurements made on DSMs obtained by several other researchers. These results indicate some of the scope and complexity challenges that KBE faces.

scholarly journals Effect of High-Temperature Pavement Paving on Fatigue Durability of Bearing-Supported Steel Decks

2020 ◽  
Vol 10 (20) ◽  
pp. 7196
Author(s):  
Qiudong Wang ◽  
Bohai Ji ◽  
Zhongqiu Fu ◽  
Hao Wang
Keyword(s):  
High Temperature ◽  
Fatigue Damage ◽  
Temperature Stress ◽  
Damage Accumulation ◽  
Considerable Effect ◽  
In Situ Monitoring ◽  
Fatigue Durability ◽  
Residual Temperature ◽  
Fatigue Damage Accumulation

Orthotropic steel deck (OSD) is a better choice for urban bridges and the replacement of damaged concrete slabs. Gussasphalt concrete (GAC) is usually adopted as the asphalt surfacing; however, the paving temperature of GAC is high, which will affect the fatigue durability of fatigable welds in OSD. In this study, such influence of high-temperature pavement paving was comprehensively investigated based on in-situ monitoring and numerical analysis. The temperature of OSD and displacement of bearings were investigated based on the monitored data and numerical results. After that, the deformation and residual temperature stress of OSD during the paving process were analyzed. On this basis, the effect of residual temperature stress on fatigue damage accumulation of OSD was investigated and discussed. Results show that the uplift and expanded deformation of OSD arise during the paving process, leading to the displacement of bearings. Residual displacement of bearings, as well as the residual temperature stress at fatigable details of OSD, is observed. The residual temperature stress has considerable effect on fatigue damage accumulation at rib-deck weld. A fatigue damage amplification factor of 1.1 is recommended for taking into consideration of the adverse effect of high-temperature pavement paving.

scholarly journals Integration of System Level CFD Simulations into the Development Process of Wind Turbine Prototypes

2020 ◽  
Vol 1618 ◽  
pp. 052007
Author(s):  
Matthias Arnold ◽  
Florian Wenz ◽  
Timo Kühn ◽  
Thorsten Lutz ◽  
Andree Altmikus
Keyword(s):  
Wind Turbine ◽  
Development Process ◽  
System Level ◽  
Cfd Simulations

Resilient Self-Reproducing Systems

2008 ◽  
Author(s):  
Amor A. Menezes ◽  
Pierre T. Kabamba
Keyword(s):  
Large Scale ◽  
Failure Modes ◽  
Approaches To Learning ◽  
System Level ◽  
Reproductive Capacity ◽  
Reconfigurable Robots ◽  
Control Schemes ◽  
Learning And Adaptation ◽  
Payload Mass ◽  
System States

This paper is motivated by the need to minimize the payload mass required to establish an extraterrestrial robotic colony. One approach for this minimization is to deploy a colony consisting of individual robots capable of self-reproducing. An important consideration once such a colony is established is its resiliency to large-scale environment or state variations. Previous approaches to learning and adaptation in self-reconfigurable robots have utilized reinforcement learning, cellular automata, and distributed control schemes to achieve robust handling of failure modes at the modular level. This work considers self-reconfigurability at the system level, where each constituent robot is endowed with a self-reproductive capacity. Rather than focus on individual dynamics, the hypothesis is that resiliency in a collective may be achieved if: 1) individual robots are free to explore all options in their decision space, including self-reproduction, and 2) they dwell preferentially on the most favorable options. Through simulations, we demonstrate that a colony operating in accordance with this hypothesis is able to adapt to changes in the external environment, respond rapidly to applied disturbances and disruptions to the internal system states, and operate in the presence of uncertainty.

KL Transform and Neural-Net Based Framework for Failure Modes Classification in Electronics Subjected to Mechanical-Shock

2011 ◽  
Author(s):  
Pradeep Lall ◽  
Prashant Gupta ◽  
Kai Goebel
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Learning Algorithm ◽  
Back Propagation ◽  
Feature Space ◽  
System Level ◽  
Neural Net ◽  
Mechanical Shock ◽  
Time Frequency ◽  
Damage Initiation

Electronic systems under extreme shock and vibration environments including shock and vibration may sustain several failure modes simultaneously. Previous experience of the authors indicates that the dominant failure modes experienced by packages in a drop and shock frame work are in the solder interconnects including cracks at the package and the board interface, pad cratering, copper trace fatigue, and bulk-failure in the solder joint. In this paper, a method has been presented for failure mode classification using a combination of Karhunen Loe´ve transform with parity-based stepwise supervised training of a perceptrons. Early classification of multiple failure modes in the pre-failure space using supervised neural networks in conjunction with Karhunen Loe´ve transform is new. Feature space has been formed by joint time frequency analysis. Since the cumulative damage may be accrued under repetitive loading with exposure to multiple shock events, the area array assemblies have been exposed to shock and feature vectors constructed to track damage initiation and progression. Error Back propagation learning algorithm has been used for stepwise parity of each particular failure mode. The classified failure modes and failure regions belonging to each particular failure modes in the feature space are also validated by simulation of the designed neural network used for parity of feature space. Statistical similarity and validation of different classified dominant failure modes is performed by multivariate analysis of variance and Hoteling’s T-square. The results of different classified dominant failure modes are also correlated with the experimental cross sections of the failed test assemblies. The methodology adopted in this paper can perform real-time fault monitoring with identification of specific dominant failure mode and is scalable to system level reliability.

Assessment of Earthquake Performance of Structures by Hybrid Simulation

2019 ◽  
Author(s):  
Amr Elnashai ◽  
Hussam Mahmoud
Keyword(s):  
Earthquake Engineering ◽  
Structural Engineering ◽  
Failure Modes ◽  
Experimental Testing ◽  
Hybrid Simulation ◽  
Element Model ◽  
Simulation Software ◽  
Full Scale ◽  
System Level ◽  
Resilient Infrastructure

With current rapid growth of cities and the move toward the development of both sustainable and resilient infrastructure systems, it is vital for the structural engineering community to continue to improve their knowledge in earthquake engineering to limit infrastructure damage and the associated social and economic impacts. Historically, the development of such knowledge has been accomplished through the deployment of analytical simulations and experimental testing. Experimental testing is considered the most accurate tool by which local behavior of components or global response of systems can be assessed, assuming the test setup is realistically configured and the experiment is effectively executed. However, issues of scale, equipment capacity, and availability of research funding continue to hinder full-scale testing of complete structures. On the other hand, analytical simulation software is limited to solving specific type of problems and in many cases fail to capture complex behaviors, failure modes, and collapse of structural systems. Hybrid simulation has emerged as a potentially accurate and efficient tool for the evaluation of the response of large and complex structures under earthquake loading. In hybrid (experiment-analysis) simulation, part of a structural system is experimentally represented while the rest of the structure is numerically modeled. Typically, the most critical component is physically represented. By combining a physical specimen and a numerical model, the system-level behavior can be better quantified than modeling the entire system purely analytically or testing only a component. This article discusses the use of hybrid simulation as an effective tool for the seismic evaluation of structures. First, a chronicled development of hybrid simulation is presented with an overview of some of the previously conducted studies. Second, an overview of a hybrid simulation environment is provided. Finally, a hybrid simulation application example on the response of steel frames with semi-rigid connections under earthquake excitations is presented. The simulations included a full-scale physical specimen for the experimental module of a connection, and a 2D finite element model for the analytical module. It is demonstrated that hybrid simulation is a powerful tool for advanced assessment when used with appropriate analytical and experimental realizations of the components and that semi-rigid frames are a viable option in earthquake engineering applications.

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