scholarly journals Fatigue Life Assessment of Revised Cope-Hole Details in Steel Truss Bridges

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1092
Author(s):  
Ping Liao ◽  
Bing Qu ◽  
Yaolong Huang ◽  
Yi Jia ◽  
Yongbao Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Amplitude ◽  
Fatigue Loading ◽  
Fatigue Performance ◽  
Life Assessment ◽  
Element Analysis ◽  
Truss Bridges ◽  
Steel Truss ◽  
Cope Hole ◽  
Steel Truss Bridges

In recent years, various welded details with complex local structure, ambiguous fatigue performance have appeared in fully welded steel truss bridges, however, they are not covered in the current design specifications. In order to study the fatigue performance of revised cope-hole details, fatigue performance experiments were designed and carried out on three specimens of revised detail with the same dimensions but subjected to different stress amplitude. Local finite element model of the revised cope-hole detail was established for further stress analysis. The results of finite element analysis were basically consistent with the static test results at majority of measurement points. Based on the existing fatigue test data and fatigue strength of cope-hole details defined in Eurocode and JSSC design code, the fatigue performance of revised cope-hole details was evaluated. The S-N fitting curve with the failure probability of 2.3% was obtained from the fatigue experiment results. The fatigue stress amplitude was 59.5 MPa when fatigue loading cycle was 2 × 106. It can be concluded that the fatigue performance of revised cope-hole detail was better than that of previous welded detail, which indicated that the revised detail had a significant improvement.

scholarly journals Condition Assessment of Joints in Steel Truss Bridges Using a Probabilistic Neural Network and Finite Element Model Updating

2021 ◽  
Vol 13 (3) ◽  
pp. 1474
Author(s):  
Jiawang Zhan ◽  
Chuang Wang ◽  
Zhiheng Fang
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Model Updating ◽  
Probabilistic Neural Network ◽  
Fe Model ◽  
Damage Localization ◽  
Truss Bridges ◽  
Steel Truss ◽  
Fe Model Updating ◽  
Steel Truss Bridges

The condition of joints in steel truss bridges is critical to railway operational safety. The available methods for the quantitative assessment of different types of joint damage are, however, very limited. This paper numerically investigates the feasibility of using a probabilistic neural network (PNN) and a finite element (FE) model updating technique to assess the condition of joints in steel truss bridges. A two-step identification procedure is developed to achieve damage localization and severity assessment. A series of FE models with single or multiple damages are simulated to generate the training and testing data samples and validate the effectiveness of the proposed approach. The influence of noise on the identification accuracy is also evaluated. The results show that the change rate of modal curvature (CRMC) can be used as a damage-sensitive input of the PNN and the accuracy of preliminary damage localization can exceed 90% when suitable training patterns are utilized. Damaged members can be localized in the correct substructure even with noise contamination. The FE model updating method used can effectively quantify the joint deterioration severity and is robust to noise.

Fatigue performance and evaluation of welded joints in steel truss bridges

2018 ◽  
Vol 148 ◽  
pp. 450-456 ◽  
Author(s):  
Chuang Cui ◽  
Qinghua Zhang ◽  
Yi Bao ◽  
Jiping Kang ◽  
Yizhi Bu
Keyword(s):  
Welded Joints ◽  
Fatigue Performance ◽  
Truss Bridges ◽  
Steel Truss ◽  
Performance And Evaluation ◽  
Steel Truss Bridges

Effect of Defect on Elastic/Plastic and Creep Behavior of Bone: A Finite Element Study

2007 ◽  
Author(s):  
A. Ajdari ◽  
P. K. Canavan ◽  
H. Nayeb-Hashemi ◽  
G. Warner
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Trabecular Bone ◽  
Fatigue Loading ◽  
Dimensional Structure ◽  
Plastic Behavior ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Local Bone ◽  
Osteoporotic Vertebral Fractures

Three-dimensional structure of trabecular bone can be modeled by 2D or 3D Voronoi structure. The effect of missing cell walls on the mechanical properties of 2D honeycombs is a first step towards understanding the effect of local bone resorption due to osteoporosis. In patients with osteoporosis, bone mass is lost first by thinning and then by resorption of the trabeculae [1]. Furthermore, creep response is important to analyze in cellular solids when the temperature is high relative to the melting temperature. For trabecular bone, as body temperature (38 °C) is close to the denaturation temperature of collagen (52 °C), trabecular bone creeps [1]. Over the half of the osteoporotic vertebral fractures that occur in the elderly, are the result of the creep and fatigue loading associated with the activities of daily living [2]. The objective of this work is to understand the effect of missing walls and filled cells on elastic-plastic behavior of both regular hexagonal and non-periodic Voronoi structures using finite element analysis. The results show that the missing walls have a significant effect on overall elastic properties of the cellular structure. For both regular hexagonal and Voronoi materials, the yield strength of the structure decreased by more than 60% by introducing 10% missing walls. In contrast, the results indicate that filled cells have much less effect on the mechanical properties of both regular hexagonal and Voronoi materials.

With Different Axial Compression, the Finite Element Analysis of Concrete Frame Column that Reinforced by Assemble Inclined Web Steel Truss

2014 ◽  
Vol 1079-1080 ◽  
pp. 177-182
Author(s):  
Shao Wu Zhang ◽  
Ying Chuan Chen ◽  
Geng Biao Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Simulation Analysis ◽  
Hysteresis Curve ◽  
Element Analysis ◽  
Concrete Frame ◽  
The Finite Element Analysis ◽  
Steel Truss

In order to study the performance of concrete frame columns that reinforcedby assembleinclined web steel truss, with the same reciprocatinghorizontal displacement and different axialcompression.It canbe calculate the mechanical behavior of concrete frame columns and reinforced columns by using the finite element analysis software ABAQUS. Simulation analysis shows that the bearing capacity ofreinforced columnshas greatly increased andpresented a full hysteresis curve. The result shows that the reinforcement method of assemble inclined web steel truss can greatly improve the bearing capacity and ductility of the concrete frame column, and the axial compression is larger, the better the reinforcement effect.

Formulation of Three-Dimensional Green’s Function and its Application to Fatigue Life Evaluation of Pressurizer

2006 ◽  
Vol 324-325 ◽  
pp. 387-390
Author(s):  
Yoon Suk Chang ◽  
Shin Beom Choi ◽  
Jae Boong Choi ◽  
Young Jin Kim ◽  
Myung Jo Jhung ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Green’S Function ◽  
Green's Function ◽  
Three Dimensional ◽  
Stress Transfer ◽  
Life Assessment ◽  
Element Analysis ◽  
Fatigue Evaluation ◽  
Effective Assessment

Major nuclear components have been designed by conservative codes to prevent unanticipated fatigue failure. However, more realistic and effective assessment is necessary in proof of continued operation beyond the design life. In the present paper, three-dimensional stress and fatigue evaluation is carried out for pressurizer employing complex full geometry itself instead of conventional discrete subcomponents. For this purpose, temperature and mechanical stress transfer Green’s functions are derived from finite element analyses and applied to critical locations of pressurizer. In accordance with comparison of resulting stresses obtained from the Green’s function and detailed finite element analysis, suitability of the specific Green’s function is investigated. Finally, prototype of fatigue life assessment results is provided along with relevant ongoing activities.

Structural Health Indices for Steel Truss Bridges

2011 ◽  
pp. 391-398 ◽  
Author(s):  
Ryan Kent Giles ◽  
Robin Kim ◽  
Billie F. Spencer ◽  
M. Nathan ◽  
Anne M. Newmark ◽  
...  
Keyword(s):  
Structural Health ◽  
Truss Bridges ◽  
Health Indices ◽  
Steel Truss ◽  
Steel Truss Bridges
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