Cyclic Loading Test and Numerical Analysis of Flange Joint and Reducer of RHR Piping Systems

2014 ◽  
Author(s):  
Zih-Yu Lai ◽  
Yan-Fang Liu ◽  
Ching-Ching Yu ◽  
Juin-Fu Chai ◽  
Fan-Ru Lin ◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Cyclic Loading ◽  
Nuclear Power ◽  
Numerical Models ◽  
Heat Removal ◽  
Piping System ◽  
Loading Test ◽  
Element Analysis ◽  
Piping Systems

According to the seismic risk assessment results presented in the Final Safety Analysis Report (FSAR) for a nuclear power plant in Taiwan, the failure of Residual Heat Removal (RHR) piping system occurs in both of the two accident sequences with the highest contributions for core damage. The seismic performance of RHR piping system depends on the capacity of its components, such as supports, flanged joints and reducers. For the need of seismic response-history analysis of RHR piping systems, we developed detailed numerical models of flanged joint and reducer using finite element analysis software (ABAQUS and SAP2000). The proposed finite element models were verified by the experimental results. The pure bending tests with four-point cyclic loading were conducted for sample flanged joint and reducer to investigate their mechanical behaviors. The displacement and rotation responses identified from the tests are in good agreement with the results of numerical analysis. A preliminary simplified model of flanged joints was also proposed in this study to improve the efficiency of numerical analysis for RHR piping system.

Experimental and Numerical Analysis of a Pristine and a Nano-Modified Thermoplastic Adhesive

2018 ◽  
Author(s):  
Carlo Boursier Niutta ◽  
Raffaele Ciardiello ◽  
Giovanni Belingardi ◽  
Alessandro Scattina
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Numerical Analysis ◽  
Mechanical Behavior ◽  
Numerical Models ◽  
Surface Preparation ◽  
Experimental Results ◽  
Element Analysis ◽  
Piping Systems ◽  
Set Up

In this work, the mechanical properties of two different adhesives compositions have been investigated both experimentally and numerically. The studied thermoplastic adhesives are Hot-Melt Adhesive (HMA). In particular, a pristine and a nanomodified adhesive with 10% in weight of iron oxide have been considered. The adhesives have been subjected to a series of single lap joint (SLJ) tests using adherends made of polypropylene copolymer. As it is well-known, the structural-mechanical behavior of adhesive joints is mostly influenced by the bonding process: thickness of adhesive as well as its application procedures and the surface preparation of adherends are among the most influencing factors. In addition, the mechanical behavior of SLJ test is particularly influenced by the correct alignment of adherends and applied load. These aspects have been investigated, analyzing the experimental results. Moreover, the experimental results have been used to develop a numerical model of the two adhesives. The numerical analysis has been carried out using the commercial software LS-DYNA. Transient nonlinear finite element analysis has been performed to simulate the mechanical behavior of the thermoplastic adhesives. In particular, the cohesive formulations of the elements have been taken into consideration after a careful literature review. In order to set-up and to validate the mechanical properties of the adhesives, the experimental SLJ tests have been simulated. The developed finite element models enable to investigate more complex joint structures where these types of adhesives are used, such as plastic piping systems and automotive applications. Further, the numerical models allow to investigate with higher accuracy and lower time different aspects such as manufacturing and non-linear effects.

Creep Life Simulation and Assessment of High Temperature Piping Systems and Components

2012 ◽  
Author(s):  
Brian Rose ◽  
James Widrig
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Creep Behavior ◽  
Material Behavior ◽  
Piping System ◽  
Remaining Life ◽  
Creep Life ◽  
Element Analysis ◽  
Piping Systems

High temperature piping systems and associated components, elbows and bellows in particular, are vulnerable to damage from creep. The creep behavior of the system is simulated using finite element analysis (FEA). Material behavior and damage is characterized using the MPC Omega law, which captures creep embrittlement. Elbow elements provide rapid yet accurate modeling of pinching of piping, which consumes a major portion of the creep life. The simulation is used to estimate the remaining life of the piping system, evaluate the adequacy of existing bellows and spring can supports and explore remediation options.

Simplified Seismic Response Analysis Method Using Reduced Model of Piping System

2018 ◽  
Author(s):  
Michiya Sakai ◽  
Ryuya Shimazu ◽  
Shinichi Matsuura ◽  
Ichiro Tamura
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Seismic Response ◽  
Degrees Of Freedom ◽  
Response Analysis ◽  
Piping System ◽  
Element Analysis ◽  
Mass System ◽  
Piping Systems ◽  
Low Degrees

In the seismic response analysis of piping systems, finite element analysis is performed with analysis method guidelines [1]–[4] established based on benchmark analysis. However, since it takes a great deal of effort to carry out finite element analysis, a simplified method to analyze the seismic response of complex piping systems is required. In this research, we propose a method to reduce an equivalent spring-mass system model with low degrees of freedom, which can take into account the main mode of the complicated piping system. Simplified seismic evaluation is carried out using this spring mass system model with low degrees of freedom, and the accuracy of response evaluation is confirmed by comparison with finite element analysis.

Development of Elastic-Plastic Constitutive Models for the Evaluation of Nuclear Piping Systems Under Severe Cyclic Loading

2012 ◽  
Author(s):  
Yukio Takahashi ◽  
Yoshihiko Tanaka
Keyword(s):  
Cyclic Loading ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Kinematic Hardening ◽  
Constitutive Models ◽  
Seismic Loading ◽  
Piping System ◽  
Elastic Plastic ◽  
Piping Systems

It is essential to predict the behavior of nuclear piping system under seismic loading to evaluate the structural integrity of nuclear power plants. Relatively large stress cycles may be applied to the piping systems under severe seismic loading and plastic deformation may occur cyclically in some portion of the systems. Accurate description of inelastic deformation under cyclic loading is indispensable for the precise estimation of strain cycles and accumulation potentially leading to the failure due to fatigue-ratcheting interaction. Elastic-plastic constitutive models based on the nonlinear kinematic hardening rule proposed by Ohno and Wang were developed for type 316 austenitic stainless steel and carbon steel JIS STPT410 (similar to ASTM A106 Gr.B), both of which are used in piping systems in nuclear power plants. Different deformation characteristics under cyclic loading in terms of memory of prior hardening were observed on these two materials and they were reflected in the modeling. Results of simulations under various loading conditions were compared with the test data to demonstrate the high capability of the constitutive models.

Elastic-Plastic Analysis of Thick-Walled Toroidal Pressure Vessels

2008 ◽  
Author(s):  
R. Adibi-Asl
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Three Dimensional ◽  
Pressure Vessels ◽  
Toroidal Shell ◽  
Piping System ◽  
Straight Pipe ◽  
Element Analysis ◽  
Process Industries ◽  
Piping Systems

Piping systems in process industries and nuclear power plants include straight pipe runs and various fittings such as elbows, miter bends etc. Elbows and bends in piping systems provide additional flexibility to the piping system along with performing the primary function of changing the direction of fluid flow. Distinctive geometry of these toroidal shell components result in a structural behavior different from straight pipe. Hence, it would be useful to predict the behavior of these components with acceptable accuracy for design purposes. Analytical expressions are derived for stresses set up during loading and unloading in a toroidal shell subjected to internal pressure. Residual stresses in the component are also evaluated. The proposed solutions are then compared with three-dimensional finite element analysis at different locations including intrados, extrados and flanks.

Safety Assessment of Slant Legged Rigid Frame Bridge Based on Field Testing

2013 ◽  
Vol 574 ◽  
pp. 163-175
Author(s):  
Yan Li ◽  
Hong Tao Bi ◽  
Bing Han Li ◽  
Yong Jun Wang
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Field Testing ◽  
Control Measures ◽  
Original Design ◽  
Loading Test ◽  
Element Analysis ◽  
Rigid Frame ◽  
Rigid Frame Bridge

The safety and load-bearing capacity of an in-service urban reinforced concrete slant leg rigid frame bridge over railway is assessed by field testing and finite element analysis. The bridge is located in Qitaihe city, the northeastern of China. The two heavy trucks and three different loading test configurations are used in experiment. The three load figuration is set up and performed based on the result of technical condition investigation and finite element numerical analysis. The vertical displacement and key section strain response are recorded during experiment. Loading-bearing capacity and safety performance of the bridge is analyzed and evaluated according to measured data combining with numerical analysis. The testing result shows that structural stiffness and strength of the bridge do not satisfy the requirements of the original design. Based on the assessment result, some proposals are proposed to the management office. A moderate maintenance and reinforcement treatment should be carried out for this bridge to improve the bearing capacity and ensure safety operation. Before that completed some traffic control measures should be taken to avoid aggravating diseases and damages of the bridge due to passing heavy vehicle.

Numerical Analysis of Flush End-Plate Beam-to-Column Connection using Mathematical Model and Finite Element Analysis

2021 ◽  
Author(s):  
Mohammad Haroon Ehsan ◽  
Mutlu Seçer
Keyword(s):  
Mathematical Model ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Numerical Models ◽  
Design Parameters ◽  
Engineering Practice ◽  
Element Analysis ◽  
Analysis And Design ◽  
End Plate

In the conventional analysis and design of steel structures, beam-to-column connections are generally assumed as entirely rigid or perfectly pinned. This assumption simplifies analysis and design steps and preferred extensively in structural engineering practice. However, experimental studies conducted in recent years have revealed that handling some of the beam-to-column connections as entirely rigid or perfectly pinned does not give realistic results. In fact, most of the connections used in current practice have some certain amount of stiffness which fall between the extreme cases of entirely rigid and perfectly pinned. In order to model the beam-to-column connections properly, several researchers have proposed various mathematical models based on experimental results. In these models, moment rotation relations of beam-to-column connections are defined according to the type of connection. In this study, moment-rotation behaviors of beam-to-column connections formed by flush end-plate are investigated using finite element analysis and a well-known practical mathematical model. Moreover, numerical analysis outcomes were compared with the test results of a reference study from the literature. This paper showed the importance of structural design parameters in determining moment-rotation relationship of flush end-plate type of beam-to-column connections and evaluated the efficiency of the practical numerical models.

Finite Element Analysis of Typical Beam-Column Joints in Yingxian Wood Pagoda

2014 ◽  
Vol 1008-1009 ◽  
pp. 1205-1208
Author(s):  
Jian Long Han ◽  
Guan Feng Qiao ◽  
Qing Fang Niu ◽  
Tie Ying Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Dissipation ◽  
Cyclic Loading ◽  
Wood Structure ◽  
Vertical Load ◽  
Loading Test ◽  
Element Analysis ◽  
Cyclic Loading Test ◽  
Ancient Wood

Yingxian Wood Pagoda is the highest standing ancient wood structure in China,with four shorter but stiffer storeys hidden between the five apparent storeys. The beam-colunm joints are highly varied. In this study,a model of typical beam-column joints of the pagoda was simulated in Abaqus. The material used in models was similar to the ones of the pagoda.Non-destructive cyclic loading test of the models under different vertical load were conducted.The hysteretic curves underdifferent vertical load were drawn from the test.And the skeleton curves were obtained by linking all peak moment points of each hysteretic loop. The energy –dissipation performance and bending stiffness of models were derived and discussed.

Numerical Analysis of a RHR Piping System Subjected to Seismic Loading

2014 ◽  
Author(s):  
Ming-Yi Shen ◽  
Zih-Yu Lai ◽  
Juin-Fu Chai ◽  
Fan-Ru Lin ◽  
Yin-Nan Huang ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Cyclic Loading ◽  
Numerical Model ◽  
Shaking Table Test ◽  
Response Spectrum ◽  
Shaking Table ◽  
Fragility Analysis ◽  
Piping System ◽  
Loading Test ◽  
Cyclic Loading Test

The objective of this study is to build a credible numerical model using SAP2000 for fragility analysis of RHR piping system, and to establish the load pattern of a cyclic loading test to identify the seismic vulnerability of the system. The RHR piping system selected for test and numerical analysis is duplicated from a part of the RHR system in a nuclear power plant (NPP) in Taiwan, and this part is distributed between the floor of the reactor building (RB) to the wall of the reinforced concrete containment vessel (RCCV) of the sample NPP. The numerical model for the sample RHR piping system was developed, and the nonlinear response-history analysis was conducted using input motions compatible with the floor response spectrum at the anchor points of the sample piping system subjected to Safe Shutdown Earthquake (SSE). Based on the distribution of resultant inertial forces and the responses at critical locations of the piping system under SSE, the magnitudes and locations of the equivalent concentrated static loads were determined and used in the pushover analysis to estimate the capacity of the RHR piping system. The numerical results will be verified by the aforementioned cyclic loading test. More studies are on the way including shaking table test and fragility analysis for the sample piping system to further identify the seismic performance and risk of the system.

Finite Element Analysis of High-Strength Concrete Flat Columns with Diagonal Reinforcements

2013 ◽  
Vol 791-793 ◽  
pp. 514-518
Author(s):  
Tuo Lei ◽  
Jiang Qian ◽  
Qing Biao Tian
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cyclic Loading ◽  
High Strength Concrete ◽  
Kinematic Hardening ◽  
High Strength ◽  
Loading Test ◽  
Element Analysis ◽  
Strength Concrete ◽  
Concrete Members

Based on the reversed cyclic loading test of three 1:4 high-strength concrete flat columns, the computer program ABAQUS was used to simulate behaviors of the specimens. Concrete in the column was modeled using the damage plasticity material model, and a uniaxial steel model with combined isotropic and kinematic hardening properties was used to simulate the behavior of the reinforcement. The establishment of the finite element model, definition of the material parameters and the influence of diagonal reinforcement were discussed at length. The results show that the concrete damage plasticity model can be well used for hysteretic analysis of reinforced concrete members if the relevant parameters are reasonably defined. Diagonal reinforcements can not significantly improve ductility of the specimens, but can improve their shear capacities. This paper can provide reference for the performance simulation of reinforced concrete members under cyclic loading.

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