scholarly journals Stressing State Analysis on a Single Tube CFST Arch Under Spatial Loads

2019 ◽  
Vol 9 (23) ◽  
pp. 5039
Author(s):  
Kangkang Yang ◽  
Jian Yuan ◽  
Jun Shi ◽  
Kaikai Zheng ◽  
Jiyang Shen
Keyword(s):  
Strain Energy Density ◽  
Strain Energy ◽  
Characteristic Curve ◽  
Arch Model ◽  
Average Strain ◽  
Bending Strain ◽  
Strain Data ◽  
Internal Forces ◽  
Arch Structures ◽  
Behavior Characteristics

This paper analyzes the stressing state characteristics of a concrete-filled steel tubular (CFST) arch model under spatial loads, using the method of modeling structural stressing state and the thin plate simulating interpolation (TSI) method. Firstly, the parameter-generalized strain energy density (GSED) is applied to model the stressing state of the arch. Then, the normalized GSED sum at each load plots the characteristic curve. The characteristic loads P (66 kN) and Q (85 kN) in the curve are distinguished by the Mann–Kendall (M–K) criterion. To characterize structural axial and bending stressing states, the parameters of the sectional average strain and generalized bending strain are proposed as stressing state submodes. Finally, the TSI method is used to interpolate strain data for deep analysis of internal forces. By modeling the structural stressing state, the working behavior characteristics of arch structures are greatly revealed in a particular view and the results could provide a reference for the development of bridge design.

A Modified Closed Form Energy Based Framework for Fatigue Life Assessment for Aluminum 6061-T6—Damaging Energy Approach

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
M.-H. Herman Shen ◽  
Sajedur R. Akanda
Keyword(s):  
Fatigue Life ◽  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Strain Range ◽  
Life Assessment ◽  
Cycle Fatigue ◽  
Average Strain ◽  
Plastic Strain Range ◽  
Fatigue Life Assessment

A previously developed energy based high cycle fatigue (HCF) life assessment framework is modified to predict the low cycle fatigue (LCF) life of aluminum 6061-T6. The fatigue life assessment model of this modified framework is formulated in a closed form expression by incorporating the Ramberg–Osgood constitutive relationship. The modified framework is composed of the following entities: (1) assessment of the average strain energy density and the average plastic strain range developed in aluminum 6061-T6 during a fatigue test conducting at the ideal frequency for optimum energy calculation, and (2) determination of the Ramberg–Osgood cyclic parameters for aluminum 6061-T6 from the average strain energy density and the average plastic strain range. By this framework, the applied stress range is related to the fatigue life by a power law whose parameters are functions of the fatigue toughness and the cyclic parameters. The predicted fatigue lives are found to be in a good agreement with the experimental data.

scholarly journals AN INVESTIGATION INTO WORKING BEHAVIOR CHARACTERISTICS OF PARABOLIC CFST ARCHES APPLYING STRUCTURAL STRESSING STATE THEORY

2019 ◽  
Vol 25 (3) ◽  
pp. 215-227 ◽  
Author(s):  
Jun Shi ◽  
Kangkang Yang ◽  
Kaikai Zheng ◽  
Jiyang Shen ◽  
Guangchun Zhou ◽  
...  
Keyword(s):  
Structural Design ◽  
Strain Energy ◽  
Failure Load ◽  
Shape Function ◽  
Qualitative Change ◽  
State Theory ◽  
State Change ◽  
Strain Data ◽  
Definition Of ◽  
Behavior Characteristics

This paper conducts the experimental and simulative analysis of stressing state characteristics for parabolic concretefilled steel tubular (CFST) arches undergoing vertical loads. The measured stain data is firstly modeled as the generalized strain energy density (GSED) to describe structural stressing state mode. Then, the normalized GSED sum Ej,norm at each load Fj derives the Ej,norm-Fj curve reflecting the stressing state characteristics of CFST arches. Furthermore, the Mann-Kendall criterion is adopted to detect the stressing state change of the CFST arch during its load-bearing process, leading to the revelation of a vital stressing state leap characteristic according to the natural law from quantitative change to qualitative change of a system. The revealed qualitative leap characteristic updates the existing definition of the CFST arch’s failure load. Finally, the accurate formula is derived to predict the failure/ultimate loads of CFST arches. Besides, a method of numerical shape function is proposed to expand the limited strain data for further analysis of the stressing state submodes. The GSED-based analysis of structural stressing state opens a new way to recognize the unseen working behavior characteristics of arch structures and the updated failure load could contribute to the improvement on the structural design codes.

scholarly journals Using the Equivalent Material Concept and the Average Strain Energy Density to Analyse the Fracture Behaviour of Structural Materials

2020 ◽  
Vol 10 (5) ◽  
pp. 1601 ◽  
Author(s):  
Sergio Cicero ◽  
Juan Diego Fuentes ◽  
Ali Reza Torabi
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Equivalent Material ◽  
Nonlinear Behaviour ◽  
Average Strain ◽  
Nonlinear Materials ◽  
Linear Elastic ◽  
Equivalent Material Concept ◽  
Material Concept

This paper provides a complete overview of the applicability of the Equivalent Material Concept in conjunction with the Average Strain Energy Density criterion, to provide predictions of fracture loads in structural materials containing U-notches. The Average Strain Density Criterion (ASED) has a linear-elastic nature, so in principle, it does not provide satisfactory predictions of fracture loads in those materials with nonlinear behaviour. However, the Equivalent Material Concept (EMC) is able to transform a physically nonlinear material into an equivalent linear-elastic one and, therefore, the combination of the ASED criterion with the EMC (EMC–ASED criterion) should provide good predictions of fracture loads in physically nonlinear materials. The EMC–ASED criterion is here applied to different types of materials (polymers, composites and metals) with different grades of nonlinearity, showing the accuracy of the corresponding fracture load predictions and revealing qualitatively the limitations of the methodology. It is shown how the EMC–ASED criterion provides good predictions of fracture loads in nonlinear materials as long as the nonlinear behaviour is mainly limited to the tensile behaviour, and how the accuracy decreases when the nonlinear behaviour is extended to the material behaviour in the presence of defects.

scholarly journals Critical Load Prediction in Notched E/Glass–Epoxy-Laminated Composites Using the Virtual Isotropic Material Concept Combined with the Average Strain Energy Density Criterion

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1057
Author(s):  
Marcos Sánchez ◽  
Sergio Cicero ◽  
Ali Reza Torabi ◽  
Majid Reza Ayatollahi
Keyword(s):  
Energy Density ◽  
Critical Load ◽  
Strain Energy Density ◽  
Isotropic Material ◽  
Strain Energy ◽  
Laminated Composites ◽  
Average Strain ◽  
Fracture Test ◽  
Load Prediction ◽  
Material Concept

This paper attempts to validate the application of the Virtual Isotropic Material Concept (VIMC) in combination with the average strain energy density (ASED) criterion to predict the critical load in notched laminated composites. This methodology was applied to E/glass–epoxy-laminated composites containing U-notches. For this purpose, a series of fracture test data recently published in the literature on specimens with different notch tip radii, lay-up configurations, and a number of plies were employed. It was shown that the VIMC–ASED combined approach provided satisfactory predictions of the last-ply failure (LPF) loads (i.e., critical loads).

scholarly journals Volume free strain energy density method for applications to blunt V-notches

2020 ◽  
Vol 28 ◽  
pp. 734-742
Author(s):  
Pietro Foti ◽  
Seyed Mohammad Javad Razavi ◽  
Liviu Marsavina ◽  
Filippo Berto
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Density Method ◽  
Free Strain
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