The Limit Load Interactions of the Brazed Aluminum Plate-Fin Heat Exchanger Header Under Combined Piping Loads

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Wei Wang ◽  
Liang Chen ◽  
Caidong Guo

In order to investigate the strength design problem of the brazed aluminum plate-fin heat exchanger header under complex external piping loads, the limit load interactions of the header under combined piping loads are studied in this paper. To establish the limit piping load interaction curves, nonlinear finite element analysis assuming the elastic perfectly plastic material model is performed by using the commercial finite element analysis software ANSYS and multiple piping load combinations, which are the combination of orthogonal bending moment components, torque component-shear force component, bending moment component-axial force component, compound bending moment-axial force component, and torque component-compound shear force, of the header with six opening ratios ranging from 0.5 to 1 are explored. The results of the interaction diagrams show that the feasible combined piping load zone of the header derived from the interaction curves can be simplified as a triangular zone determined by the individual limit piping load components safely and the simplified feasible zone is suggested to be used for establishing a simplified safety assessment method for the header under combined piping loads.

Author(s):  
Weijie Jiang ◽  
Jianping Zhao ◽  
Dingyue Chen

A tensile test of buried PE pipe is designed to test the mechanical performance. Then the constitutive model for the PE pipe can be established. The limit load of the PE pipe with local thinning defect can be studied with the method of combining the orthogonal design of experiment and finite element analysis. Then the factors of local thinning defect pipe limit load factors can be analyzed. The results show that the depth of the defect has a great effect on the limit load (internal pressure and bending moment) of PE pipe. The effects that the axial length of the defect and the circumferential length of the defect have on the limit load are not significant.


2013 ◽  
Vol 774-776 ◽  
pp. 1090-1097 ◽  
Author(s):  
Zhi Xiang Duan ◽  
Kun Shi

This paper discusses the plastic limit load of elbows without defects and with local thinned area (LTA) in the extrados under combined pressure and in-plane closing bending moment. Finite element analysis (FEA) and experiments have been used. The results of FEA show that, for the elbows without defects, when the ratio of pressure to the limit pressure (P/PL) is smaller than 0.469, the limit moment of elbows increases with the increasing pressure; when the ratio (P/PL) is bigger than 0.469, the limit moment of elbow decreases with the increasing pressure. For the elbows with LTA, the FEA results show that with different LTA the variation of the limit load of elbows to the pressure is different. Perhaps, the limit moment of elbows always decreases with the increasing pressure. It is also likely that the limit moment of elbows increases with the increasing pressure and then decreases with the increasing pressure. The results of FEA are consistent with the experimental results. By fitting the results of FEA, the safety assessment figure for elbows under combined pressure and in-plane closing bending moment is drawn.


2019 ◽  
Vol 8 (2) ◽  
pp. 4874-4879

In every structure, the super structure and the foundation executed on soil, represent an entire structural system. The analysis of a framed structure while not modeling its foundation system and its rigidity could mislead the axial forces, moments due to bending and due to settlement. It is, thus necessary to hold out the analysis considering the type of soil, foundation and above the sub structure i.e. (super structure). Hence the analysis of the single bay single storied building frame resting on soil (Clayey Soil) is taken for present study. The analysis is carried out using “ANSYS 16.0”. In this paper the effect of soil interaction on building frame design parameters as change of modulus of sub-grade reaction from 0.010 to 0.050 N/mm3 .Shear force, Bending moment and settlements have been studied for different footing sizes of 1mx1m to 4.5mx4.5m the effect of SSI is quantified using finite element analysis. The following conclusions have been drawn from the study, the shear force and axial force value in the beam and column is constant from finite element analysis are not having considerable difference. The analysis is predicting that percentage difference in bending moment in beam, column and footings are at lower EFS value i.e 0.010N/mm3 at lower footing size 1mX1m is greater than when compared to higher EFS value i.e 0.050N/mm3 at higher footing size 4.5mX4.5m which considers soil interaction. But in case of the footings they undergo some settlement the percentage difference of settlement is 14.41% and 6.72% at lower EFS value i.e 0.010N/mm3 at lower footing size 1mx1m when compared to higher EFS value i.e 0.050N/mm3 at higher footing size 4.5mx4.5m respectively, which considers soil interaction.


Author(s):  
Xiaoqing Teng

Primary structural components of a spar hull are designed to resist lateral hydrodynamic and hydrostatic pressure and global loads. The scantlings of each primary component are usually determined based on the largest pressure it may encounter in various phases such as wet-tow, upending, and in-place operational conditions. The effect of global bending moment and shear force on the spar hull is often evaluated much later via laborious finite element analysis. This paper proposes a simple analytical tool for quickly assessing global hull strength of classic spars in the in-place condition. A spar platform undergoes steady, low-frequency, and wave-frequency motion of comparable magnitude at the same time in a storm event. The present approach separates the wave-frequency component from the steady and low-frequency response. A closed-form solution is developed for wave-induced motion and loads by taking advantage of the simple cylindrical shape of classic spar hulls. The theoretical solution is verified by comparing to numerical WAMIT results. The low-frequency response is approximated as one part of the steady response, since its dynamic effect is weak. The steady structural response is mainly a function of the heel angle. It is demonstrated that local effect of wind pressure and current load is not significant. The total response, as a summation of the wave-induced loads and the steady solution, is represented by global bending moment and shear force envelopes along the spar hull for a given sea state. Global bending and shear stresses of primary structural components can be further calculated and checked against code requirements. This procedure has been implemented through Matlab scripts. A comparison with global finite element analysis for a classic spar is made showing very good agreement. The present simple procedure allows us to evaluate primary structural components of a spar hull without resorting to expensive finite element modeling. It can help the scantling design by providing the global load. The approach can also be used to identify critical environmental conditions and structural components for detailed finite element analysis.


2014 ◽  
Vol 945-949 ◽  
pp. 1135-1138
Author(s):  
Tao Liang ◽  
Chun Ling Meng ◽  
Yang Li ◽  
Xiu Hua Zhao

The finite element analysis of large air cooling tower was carried out using ABAQUS. On the basis of strength above,8 types of the axial force are analyzed and summarized, find valuable rules, and put forward the further optimization design. So that it can satisfy the strength and stability of air cooling tower, the structure is more reasonable, reduce weight, reduce the cost.


2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.


2017 ◽  
Vol 62 (3) ◽  
pp. 1881-1887
Author(s):  
P. Ramaswami ◽  
P. Senthil Velmurugan ◽  
R. Rajasekar

Abstract The present paper makes an attempt to depict the effect of ovality in the inlet pigtail pipe bend of a reformer under combined internal pressure and in-plane bending. Finite element analysis (FEA) and experiments have been used. An incoloy Ni-Fe-Cr B407 alloy material was considered for study and assumed to be elastic-perfectly plastic in behavior. The design of pipe bend is based on ASME B31.3 standard and during manufacturing process, it is challenging to avoid thickening on the inner radius and thinning on the outer radius of pipe bend. This geometrical shape imperfection is known as ovality and its effect needs investigation which is considered for the study. The finite element analysis (ANSYS-workbench) results showed that ovality affects the load carrying capacity of the pipe bend and it was varying with bend factor (h). By data fitting of finite element results, an empirical formula for the limit load of inlet pigtail pipe bend with ovality has been proposed, which is validated by experiments.


2011 ◽  
Vol 52-54 ◽  
pp. 43-48 ◽  
Author(s):  
Al Emran Ismail ◽  
Ahmad Kamal Ariffin ◽  
Shahrum Abdullah ◽  
Mariyam Jameelah Ghazali ◽  
Ruslizam Daud

This paper presents a non-linear numerical investigation of surface cracks in round bars under bending moment by using ANSYS finite element analysis (FEA). Due to the symmetrical analysis, only quarter finite element (FE) model was constructed and special attention was given at the crack tip of the cracks. The surface cracks were characterized by the dimensionless crack aspect ratio, a/b = 0.6, 0.8, 1.0 and 1.2, while the dimensionless relative crack depth, a/D = 0.1, 0.2 and 0.3. The square-root singularity of stresses and strains was modeled by shifting the mid-point nodes to the quarter-point locations close to the crack tip. The proposed model was validated with the existing model before any further analysis. The elastic-plastic analysis under remotely applied bending moment was assumed to follow the Ramberg-Osgood relation with n = 5 and 10. J values were determined for all positions along the crack front and then, the limit load was predicted using the J values obtained from FEA through the reference stress method.


2014 ◽  
Vol 11 (4) ◽  
pp. 65-69
Author(s):  
Patil Tushar Vishwas ◽  
◽  
Supale Jayant P ◽  
Vinaay Patil

2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.


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