Finite-Element Model-Based Fault Prognosis on Key Components of the Reciprocating Compressor

Author(s):  
Wenqing Lu ◽  
Laibin Zhang ◽  
Wei Liang ◽  
Shuguo Li

The reciprocating compressor has become one of the most important equipments in petroleum and chemical industry. Study on vibration of the reciprocating compressor has a great significance to monitor the safety and reliability of the compressor. But it’s very difficult to predict the compressor and achieve the desired goal due to the complicated structure and operational aspect of the compressor. Experimental solution is expensive and time consuming. Therefore, finite element analysis (FEA) method is proposed to predict and locate the breakage of several key components on reciprocating compressor in compressor station. Non-destructive fault diagnosis and troubleshooting of the compressor can be achieved by application of FEA. The reasonable and simplified 3D model of the reciprocating compressor, which is validated with the actual prototype, is built by a CAD drawing software-SolidWorks. Then the ANSYS FE model is created by importing the 3D model into a FEA software-ANSYS. The ANSYS FE model can be used for stress analysis as well as intrinsic property analysis of the structural components. In this paper there are several ANSYS FE models of key components presented, including crankshaft, connecting-rod, crosshead and air valve. Then FEA method is applied to the fault localization of those components. According to the simulation results, the sites vulnerable to failure can be fixed on key components. The conclusions are consistent with the problems during the normal operation. Therefore, FEA is an effective and prospective method on fault prognosis of the reciprocating compressor.

Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.


Author(s):  
J. Rodriguez ◽  
M. Him

Abstract This paper presents a finite element mesh generation algorithm (PREPAT) designed to automatically discretize two-dimensional domains. The mesh generation algorithm is a mapping scheme which creates a uniform isoparametric FE model based on a pre-partitioned domain of the component. The proposed algorithm provides a faster and more accurate tool in the pre-processing phase of a Finite Element Analysis (FEA). A primary goal of the developed mesh generator is to create a finite element model requiring only essential input from the analyst. As a result, the generator code utilizes only a sketch, based on geometric primitives, and information relating to loading/boundary conditions. These conditions represents the constraints that are propagated throughout the model and the available finite elements are uniformly mapped in the resulting sub-domains. Relative advantages and limitations of the mesh generator are discussed. Examples are presented to illustrate the accuracy, efficiency and applicability of PREPAT.


Author(s):  
Mohammad S. Davoud ◽  
Xiaomin Deng

Predictions of transient temperature distributions in welding can help the selection of welding process parameters that minimize residual stresses. A three-dimensional (3D) thermal finite element model of bead-on-plate gas metal are welding (GMAW) is presented and is used to evaluate a cross-sectional, two-dimensional (2D) counterpart model. While the thermomechanical problem of welding is 3D in nature, it is shown that the 2D model can provide temperature field predictions comparable to those of the 3D model, even though the 2D model tends to predict peak temperatures higher than those of the 3D model. Both types of model predictions are compared to welding test measurements.


1998 ◽  
Vol 33 (4) ◽  
pp. 263-274 ◽  
Author(s):  
D J Smith ◽  
C G C Poussard ◽  
M J Pavier

Measurements of residual stresses in 6 mm thick aluminium alloy 2024 plates containing 4 per cent cold worked fastener are made using the Sachs method. The measurements are made on discs extracted from the plates. The measured tangential residual stress distribution adjacent to the hole edge are found to be affected by the disc diameter. The measured residual stresses are also in good agreement with averaged through-thickness predictions of residual stresses from an axisymmetric finite element (FE) model of the cold working process. A finite element analysis is also conducted to simulate disc extraction and then the Sachs method. The measured FE residual stresses from the Sachs simulation are found to be in good agreement with the averaged through-thickness predicted residual stresses. The Sachs simulation was not able to reproduce the detailed near-surface residual stresses found from the finite element model of the cold working process.


2015 ◽  
Vol 733 ◽  
pp. 591-594
Author(s):  
Yong Zhen Zhu ◽  
Kuo Yang ◽  
Qi Yang ◽  
Yun De Zhao

The CAD software was used to establish 3D model of frame of dump truck, and the finite element model was established through Hyper Mesh. The stress distributions of the frame in vertical accelerating, turning, twisting and climbing conditions were computed through finite element software when the dump truck was loaded 80t. The result is consistent with the actual situation of the frame, which proved that the approach of finite element analysis is feasible. And we proposed the improved method of the frame according to finite element results.


2017 ◽  
Vol 21 (2) ◽  
pp. 422-438 ◽  
Author(s):  
G Martakos ◽  
JH Andreasen ◽  
C Berggreen ◽  
OT Thomsen

A novel crack arresting device is implemented in foam-cored composite sandwich beams and tested using the Sandwich Tear Test (STT) configuration. A finite element model of the setup is developed, and the predictions are correlated with observations and results from a recently conducted experimental fatigue test study. Based on a linear elastic fracture mechanics approach, the developed FE model is utilised to simulate crack propagation and arrest in foam-cored sandwich beam specimens subjected to fatigue loading conditions. The effect of the crack arresters on the fatigue life is analysed, and the predictive results are subsequently compared with the observations from the previously conducted fatigue tests. The FE model predicts the energy release rate and the mode mixity based on the derived crack surface displacements, utilising algorithms for the prediction of accelerated fatigue crack growth as well as the strain field evolution in the vicinity of the crack tip on the surface of the sandwich specimens. It is further shown that the developed finite element analysis methodology can be used to gain a deeper insight onto the physics and behavioural characteristics of the novel peel stopper concept, as well as a design tool that can be used for the implementation of crack arresting devises in engineering applications of sandwich components and structures.


2013 ◽  
Vol 744 ◽  
pp. 190-193
Author(s):  
Xiu Hua Ma

According to the plunger pump movement principle, this paper analyzed the two kind of typical force situation of the connecting rod, and obtained the theoretical maximum value of the force. The finite element analysis method was applied to analyze the structure strength of the connecting rod. The finite element model of the connecting rod was established, and the load handling and boundary condition was analyzed. The maximum stress 405MPa occurs at the transition from the small end to the link body. The average stress of the link body is 136MPa. The maximum displacement is 0.17mm, belongs to the small deformation range. The last results of the node stress and displacement show that the connecting rod can work safely.


Author(s):  
Prabin Pathak ◽  
Y. X. Zhang

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.


Author(s):  
A. Ivanov ◽  
A. Kiapour ◽  
N. Ebraheim ◽  
V. K. Goel

The sacrum fractures are very severe trauma which frequently accompanied with lumbar spine fractures. The surgical procedures often require primary stabilization of both lumbar spine and sacrum. To understand the rationale of the instrumentation numerous cadaveric studies were conducted to elucidate the anatomy of fractures and treatment options [1,2,3]. The modern computer technology allowed simulating the fractures and repairing using the Finite Element Analysis, also [4,5]. The last method has a raw of advantages versus cadaveric method such as higher reliability, accuracy, and safety. Finite element investigations of the pelvic fractures allowed comparing the influence of implants on pelvis stability. However, the extensive search of the literature failed to find a finite element model which includes the pelvis and lumbar spine together. Current study is the first step to accomplish this goal. An experimentally validated model of ligamentous lumbar spine was combined with the FE model of pelvis [7], and simulation of the sacrum fractures was conducted.


Author(s):  
Bin-yan Yu ◽  
Quan-ke Feng ◽  
Xiao-ling Yu

With the continuous trend toward high speed and large size, the reciprocating compressor crankshaft faces more serious potential threat of crack due to vibration. Therefore, early stress analysis of the crankshaft must be done thoroughly in the design stage. This article introduces a method, which combines flexible body dynamic and finite element analysis to calculate stress of the crankshaft. In this method, the load variation with time is obtained by flexible body dynamics simulation of crank and connecting rod mechanism. After that loads are loaded on finite element model of the crankshaft, and then the stress of the crankshaft is calculated in time domain. This stress can be utilized to do fatigue analysis and predict the life of crankshaft. Using this method, stress of a practical crankshaft, belonging to 6M51 reciprocating compressor, is calculated. The result showed that the maximum von Mises stress is 158 MPa, and the estimated life, which was calculated by Palmgren–Miner linear damage accumulation theory, is 2.0230e + 007 hours.


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