scholarly journals Kinematic and Static Solutions for Beam Column with Nonlinear Springs Using the Extended Linear Matching Method

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bin Gao ◽  
Jun Wu
Keyword(s):  
Potential Energy ◽  
Strain Softening ◽  
Peak Load ◽  
Matching Method ◽  
Control Approach ◽  
Good Convergence ◽  
Nonlinear Springs ◽  
Static Solutions ◽  
Perfect Plastic ◽  
Linear Matching Method

In this paper, the kinematic and static solutions for solving the static response of the beam column with nonlinear springs are presented by adopting the extended linear matching method (LMM). The extended LMM can be used to predict the displacement response of the beam-column system consisting of perfectly plastic and strain-softening materials. It is found that the kinematic solution generated by the extended LMM demonstrates a monotonic decrease for perfect plastic materials with certain restrictions on the yield surface. The potential energy of the system is proved to decrease with iterations for both perfect plastic and strain-softening materials if the loading multiplier remains constant. The extended LMM method is then applied to analyse the response of the pile system in a 3-leg offshore platform. An incremental procedure is recommended to determine the peak load for the soil exhibiting strain-softening. A displacement-control approach is used with the loading multiplier obtained from the variation of the potential energy. Good convergence of the method is obtained.

scholarly journals Research on the Performance of Electric Vehicles in Peak Load Shifting

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Qingshan Xu ◽  
Yujun Liu ◽  
Maosheng Ding ◽  
Pingliang Zeng ◽  
Wei Pan
Keyword(s):  
Potential Energy ◽  
Electric Vehicles ◽  
Peak Load ◽  
Load Shifting ◽  
Vehicle To Grid ◽  
Capacity Level ◽  
Simulation Results ◽  
The Relationship

Electric vehicles (EVs) are developing remarkably fast these years which makes the technology of vehicle-to-grid (V2G) easier to implement. Peak load shifting (PLS) is an important part of V2G service. A model of EVs’ capacity in V2G service is proposed for the research on PLS in this paper. The capacity is valued in accordance with three types of situations. Based on the model, three different scenarios are suggested in order to evaluate the capacity with MATLAB. The evaluation results indicate that EVs can provide potential energy to participate in PLS. Then, the principle of PLS with EVs is researched through the analysis of the relationship between their power and capacity. The performance of EVs in PLS is also simulated. The comparison of two simulation results shows that EVs can fulfill the request of PLS without intensely lowering their capacity level.

scholarly journals Creep Fatigue Life Assessment of a Pipe Intersection with Dissimilar Material Joint by Linear Matching Method

2016 ◽  
Vol 853 ◽  
pp. 366-371
Author(s):  
Daniele Barbera ◽  
Hao Feng Chen ◽  
Ying Hua Liu
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Direct Method ◽  
Life Assessment ◽  
Dissimilar Material ◽  
Matching Method ◽  
Fatigue Life Assessment ◽  
Creep Fatigue ◽  
The Impact ◽  
Linear Matching Method

As the energy demand increases the power industry has to enhance both efficiency and environmental sustainability of power plants by increasing the operating temperature. The accurate creep fatigue life assessment is important for the safe operation and design of current and future power plant stations. This paper proposes a practical creep fatigue life assessment case of study by the Linear Matching Method (LMM) framework. The LMM for extended Direct Steady Cycle Analysis (eDSCA) has been adopted to calculate the creep fatigue responses due to the cyclic loading under high temperature conditions. A pipe intersection with dissimilar material joint, subjected to high cycling temperature and constant pressure steam, is used as an example. The closed end condition is considered at both ends of main and branch pipes. The impact of the material mismatch, transitional thermal load, and creep dwell on the failure mechanism and location within the intersection is investigated. All the results demonstrate the capability of the method, and how a direct method is able to support engineers in the assessment and design of high temperature component in a complex loading scenario.

scholarly journals Shakedown Analysis of a Composite Cylinder With a Cross-Hole

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Haofeng Chen ◽  
Weihang Chen ◽  
Tianbai Li ◽  
James Ure
Keyword(s):  
Composite Cylinder ◽  
Temperature Dependent ◽  
Matching Method ◽  
Shakedown Analysis ◽  
Plasticity Limit ◽  
Material Discontinuities ◽  
Effects Of Temperature ◽  
Shakedown Limit ◽  
Composite Cylinders ◽  
Linear Matching Method

In this study, both the lower and upper bound shakedown limits of a closed-end composite cylinder with or without a cross-hole subject to constant internal pressure and a cyclic thermal gradient are calculated by the linear matching method. Convergence for the upper and lower bound shakedown limits of the composite cylinders is sought and shakedown limit interaction diagrams of the numerical applications identifying the regions of reverse plasticity limit and ratchet limit are presented. The effects of temperature-dependent yield stress, material discontinuities, composite cylinder thickness, and the existence of the cross-hole on the shakedown limits are discussed for different geometry parameters. Finally, a safety shakedown envelope is created by formulating the shakedown limit results of different composite materials and cylinder thickness ratios with different cross-hole sizes.

A Novel Fatigue Evaluation Approach with Direct Steady Cycle Analysis (DSCA) Based on the Linear Matching Method (LMM)

2019 ◽  
Vol 795 ◽  
pp. 383-388 ◽  
Author(s):  
Xiao Tao Zheng ◽  
Zhi Yuan Ma ◽  
Hao Feng Chen ◽  
Jun Shen
Keyword(s):  
Fatigue Life ◽  
Evaluation Method ◽  
Low Cycle Fatigue ◽  
Effective Strain ◽  
Strain Range ◽  
Matching Method ◽  
Evaluation Approach ◽  
Perfectly Plastic ◽  
Fatigue Evaluation ◽  
Linear Matching Method

The traditional Low Cycle Fatigue (LCF) evaluation method is based on elastic analysis with Neuber’s rule which is usually considered to be over conservative. However, the effective strain range at the steady cycle should be calculated by detailed cycle-by-cycle analysis for the alternative elastic-plastic method in ASME VIII-2, which is obviously time-consuming. A Direct Steady Cycle Analysis (DSCA) method within the Linear Matching Method (LMM) framework is proposed to assess the fatigue life accurately and efficiently for components with arbitrary geometries and cyclic loads. Temperature-dependent stress-strain relationships considering the strain hardening described by the Ramberg-Osgood (RO) formula are discussed and compared with those results obtained by the Elastic-Perfectly Plastic (EPP) model. Additionally, a Reversed Plasticity Domain Method (RPDM) based on the shakedown and ratchet limit analysis method and the DSCA approach within the LMM framework (LMM DSCA) is recommended to design cyclic load levels of LCF experiments with predefined fatigue life ranges.

scholarly journals Linear Matching Method for Parametric Studies of Weldments Creep-Fatigue Endurance

2013 ◽  
Author(s):  
Yevgen Gorash ◽  
Haofeng Chen
Keyword(s):  
Bending Moment ◽  
Evaluation Procedure ◽  
Geometrical Parameters ◽  
Matching Method ◽  
Individual Parameter ◽  
Creep Fatigue ◽  
Parametric Studies ◽  
Fatigue Evaluation ◽  
Fatigue Endurance ◽  
Linear Matching Method

This paper presents parametric studies on creep-fatigue endurance of the steel AISI type 316N(L) weldments defined as types 1, 2 and 3 according to R5 Vol. 2/3 Procedure classification at 550°C. The study is implemented using the Linear Matching Method (LMM) and based upon previously developed creep-fatigue evaluation procedure considering time fraction rule. Several geometrical configurations of weldments with individual parameter sets, representing different fabrication cases, are developed. For each of configurations, the total number of cycles to failure N* in creep-fatigue conditions is assessed numerically for different loading cases. The obtained set of N* is extrapolated by the analytic function dependent on normalised bending moment M̃, dwell period Δt and geometrical parameters. Proposed function for N* shows good agreement with numerical results obtained by the LMM. Therefore, it is used for the identification of Fatigue Strength Reduction Factors (FSRFs) intended for design purposes and dependent on proposed variable parameters.

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