Flange Part Research Articles

A fault diagnosis approach for flange stabilizer based on multi-signal fusion

Abstract As an essential means of energy transportation, pipelines have been widely used in various fields. However, many external factors such as vibration and corrosion can cause damage at the flange part, which seriously affects the safety of pipeline transportation. Quite a number of methods for troubleshooting at pipeline flanges have been continuously proposed, yet there is little research on diagnostic methods for the stabilizer at the flange. Therefore, in this paper, we focus on the stabilizer of the flange and a method that combines traditional detection and machine learning with each other to detect stabilizer faults is proposed. At first, we can obtain a stable and reliable diagnostic data by combining the advantages of the preload of the bolt and the acoustic signal. Subsequently, the optimized N-Beats model is trained based on the measured bolt preload data to predict the service state of the stabilizer. Finally, the data measured by the sensors as well as the predicted data are analyzed by a simplified classification algorithm to determine whether a fault has occurred and to classify the fault. The fault detection method used in this paper not only improves the accuracy of detection and shortens the fault detection time, but also improves the automation level of pipeline inspection. Hence, the work done in this paper has far-reaching practical significance for ensuring the safe and stable operation of pipelines.

Modeling and free vibration analysis of bolted composite flanged cylindrical-cylindrical shells under partial bolt loosening conditions

The bolted composite coupled cylindrical shell is a common substructure in modern engineering, which may encounter the issue of local loosening conditions during service. Meanwhile, the influence of flanges on the structural vibration characteristics is often overlooked in dynamic numerical analysis. In this paper, a semi-analytical dynamic model for the bolted composite flanged cylindrical-cylindrical shell structure under arbitrary connection conditions is established, and the free vibration characteristics of locally loose structures are emphatically studied. In the model, the annular plate modeling method is developed to achieve the simulation of the flange part. To fully reflect the connection characteristics of the bolted joint, a spring surface model and the corresponding parameter determination method based on fractal contact theory are developed. The equations of motion of the structure are obtained utilizing the Lagrange equations. The accuracy of the model and its predictive ability for the vibration characteristics of the bolted composite flanged cylindrical-cylindrical shell under local loosening conditions are fully demonstrated through numerous comparisons with experimental results from other literature and modal test results obtained under various working conditions. Furthermore, the influence of the number and degree of loosening bolts on the free vibration characteristics of the structure and the coupling phenomenon between different modes are discussed. The research in this paper is expected to provide references for the design of bolted composite flanged cylindrical shell structures and the monitoring of bolt connection defects.

Assessing lateral torsional buckling of stepped steel I beams using finite element method

The use of steel beams with variable sections along their length is getting more attention in recent years. These variable sections can vary gradually along the beam or change abruptly as a drop or a step. The current study investigates the lateral torsional buckling (LTB) of stepped steel beams with flanged I section subjected to uniformly distributed pressure on the top flange. The studied parameters are the step height, the step length, and the boundary conditions of the beam. The finite element method is used to carry out a linear buckling analysis of the beams’ models. The results show significant degradation in beams LTB strength due to the jump of the beam's section. Reducing the simply supported beam depth by 25 % reduces LTB strength by about 40–50 %, while reducing the fixed beam depth by 25 % reduces LTB strength by about 30–40 %. Further reduction in depth showed no significant additional reduction in simply supported beams strength, while the fixed beams showed another 30–40 % reduction in strength with another 25 % reduction in beam total depth. The step made the compressive stress transfer between the two flange parts through the web.

Research on toolpath optimization of robot-assisted incremental flanging

Robot-assisted incremental flanging (RAIF), a cost-effective and promising forming technology for producing large-size open-edge flanged parts in multi-variety and small batches, is expected to be widely used in aerospace, automotive and other technological industries. As a multi-pass incremental forming technique, the forming quality of the flanged parts is dependent on the movement of the roller controlled by the robot directly. The toolpath of a certain pass is determined by the rotation velocity (to adjust the flanging angle), the revolution velocity (to complete the flanging process of the whole blank sheet) and the matching relationship between two velocities (synchronously or asynchronously). In this paper, the process principle of RAIF technology is illustrated by using the example of shrink flanging firstly, then the effects of asynchronous motion and synchronous motion on the forming quality of a 60° flanged part made of the 5A06 aluminum alloy are compared while the rotation and revolution velocity of the roller are set to 1°/s and 1.8°/s, respectively. Results show that the forming quality is improved significantly that the maximum height of edge waves is decreased from 2.1 mm to 0.19 mm when the roller is set to rotate and revolve synchronously. Based on the above comparison results, the rotation velocity is set as 1°/s, 1.33°/s, 2°/s and 4°/s respectively to further investigate the effect of different toolpaths on the forming quality under synchronous motion conditions. It can be found that the maximum stress gradually increases from 575.4 MPa to 621.6 MPa when the rotation velocity decreases from 4°/s to 1°/s.

A New Design for Low Flange-wear Railroad Wheelset

Background: The wear of wheelsets on curves has always been a problem for rail vehicles; it is of great significance to research and develop radial components with excellent curve negotiating performance. Objective: This paper aims to study and design a wheelset with excellent curve negotiating performance to reduce wear on the flange. In addition, the dynamic simulation performance of the wheelset is studied. Methods: The wheel is divided into the flange part and the tread part; bearings are mounted between the two, allowing them to rotate at differential speeds, while the tread part maintains a rigid connection with the axle. Modeling and dynamics simulation of the wheelset is carried out by SOLIDWORKS and SIMPACK. Results: Based on the Archard wear model, it is found that the flange wear amount of the designed wheelset is significantly reduced compared with the traditional wheelset. Conclusion: The results show that the structural design of the wheelset is reasonable, has good curve negotiating performance, and can greatly reduce the wear of the flange; however, there is still room for further optimization of the structural design.

Fatigue life prediction of double-row tapered roller bearings considering thermal effect

Thermal effects on fatigue life were investigated by analyzing the thermomechanical behavior of double-row tapered roller bearings (DTRBs) and a fatigue life prediction model was developed. A bearing’s mechanical behavior was analyzed using a quasi-static model and its thermal behavior was analyzed using a thermal network method. Viscous drag and sliding friction at the contact area were considered as heat generation factors for DTRBs. The bearing lubrication characteristics and shape dimensions interacted with the temperature and the analysis was repeated until the entire DTRB system’s temperature converged. DTRB fatigue life was estimated using a fatigue life formula based on Gupta and Zaretsky’s statistical model. Results confirmed that the fatigue life decreased rapidly because of an interference fit that occurred at very high rotation speeds or at very low supply oil flow rates. This interference fit phenomenon is caused by thermal expansion of the bearing element. The interference fit can be prevented by designing with a large initial clearance value, but an initial clearance that is too large affects fatigue life negatively because of load distribution imbalance. Optimal design of the roller end sphere radius to minimize sliding friction for the flange part can provide additional help in preventing interference fit.

Local flanging process on a curved wind deflector using electromagnetic forming

Electromagnetic forming (EMF) is a high-speed forming method which utilizes non-contact electromagnetic force to achieve forming compared with the traditional stamping process. Server spring-back and poor surface quality during the traditional forming process, which would lead to low geometrical accuracy and unacceptable painting quality, are two major problems challenging the manufacture of the curved products. In this study, the EMF process and deformation behavior of curved plate were analyzed by experimental and numerical methods. The experimental result showed that the initial profile from blank unfold-bend approach was unable to achieve reasonable flanging accuracy. Based on the simulation model, the deformation process from multiple aspects, such as electromagnetic force, velocity, impact process, strain state and distribution, was investigated and inconsistent deformation behavior of the work-piece was revealed. A design process of initial profile was carried out with the aid of simulation method and the deviations between the front edge of flanged part to the die profile were quantified. Although the average deviation was reduced to 0.384 mm in geometrical deviation-based compensation method, compared to other regions, the deviations reduced significantly were found from the area corresponding to region with the large radial strain. A geometric compensation method was proposed which took the radial strain into consideration as a factor. The simulation results demonstrated that the excessive deviations of forming profile decreased to a very low level and the feasibility of the approach was verified by experiments. The final average deviation was 0.229 mm.

Numerical simulation and experimental study on electromagnetic punching-flanging process of 6061 aluminum alloy sheets

In order to shorten flanging process and improve manufacturing efficiency, an electromagnetic punching-flanging (EMPF) process was proposed in this work. The EMPF experiments were performed with 6061 aluminum alloy sheets and an electromagnetic-mechanical-fracture numerical simulation was established. The flange formation mechanism and relationships between die-fitting gaps/flange heights and discharge energies were analyzed. The thickness reductions of flanged parts were measured to characterize the flange forming quality. Results showed that sheet deformations during EMPF process mainly occurred in the flanging stage of sheets, and the relationship between flange heights and discharge energies could be represented by a quadratic function. The appropriate increase of discharge energies could reduce the die-fitting gaps. The die-fitting gap (0.506 mm) was minimum under the discharge energy of 7 kJ, which was an optimum discharge energy in this work. The thickness reduction gradually slowed down from this position to fillet positon. The maximum and average thickness reduction rates relative to sheet thickness were 13.6 % and 8.2 % for optimum discharge energy, respectively. Numerical simulation and experimental investigations illustrated that the electromagnetic punching-flanging process can be used for manufacturing flanged parts with high quality.

Finding and analyzing of the energy and force parameters of the flange formation process by orbital stamping by rolling

A characteristic feature of the details considered in the article is the increased diameter of the flange. At the Department of Aircraft Production Technology of the Scientific and Educational Mechanical and Mechanical Engineering Institute of the Kyiv Polytechnic Institute named after Igor Sikorskyi developed an original technological process for manufacturing products with a developed flange part using the positive effects of the progressive rolling stamping method. The method has energy-strength advantages over traditional methods of manufacturing parts with relatively thin structural elements. The center of application of such technologies is expanding more and more, but the basic technological calculations of process parameters have not yet been introduced widely enough into production practice. The proposed sequence of technological calculations and basic parameters of specialized installations for rolling stamping.

Computational study to predict the thermal performance and optimal design parameters of a T-shaped fin subjected to natural convection

The present paper aims to predict the optimal design parameters of a T-shaped fin subjected to natural convection using constructal theory. Both analytical and computational investigations are performed to determine its thermal performance for a wide range of thermo-physical and geometric parameters. Power law type temperature-dependent heat transfer coefficient is assumed for natural convection. For analytical solution Adomian decomposition method is adopted to evaluate the temperature distribution in both the stem and flange part of the fin. A numerical scheme called finite difference method is implemented to validate the analytical results. The temperature distribution obtained from the computational analysis using ANSYS FLUENT 14.0 is lower than that obtained from the analytical calculations. Moreover, the actual heat transfer rate is also compared between the two methods which reveal that the computational analysis gives higher value as compared to the analytical results. Further, optimization study has also been carried out in a generalized way so that either the fin volume or the heat transfer rate can be taken as a constraint. It is found that with the increase in length ratio, the optimum effectiveness is obtained at a higher value of aspect ratio whereas the optimum efficiency is obtained at a lower value of it. Though, a decrease in thickness ratio predicts a higher value of actual dimensionless heat transfer rate.

Numerical Quantification Model and Experiment of External Force on Roller Hemming of Curved Edge Aluminium Alloy with Adhesive

Accurate quantification of external force is the key to improve the high-precision hemming of autobody closure panels. However, the mechanism of external force on forming quality of complex contour sheet metal with adhesive is not clear subjected to geometric curvature and materials. In the present study, taking the curved edge aluminum sheet as the research object, SPH (smooth particle hydrodynamics) is introduced to simulate the viscous adhesive, and the SPH-FEM (Finite element method) coupling model of adhesive and panels considering the viscosity-pressure effect is established. The numerical simulation of the roller hemming process is carried out, then the validity and reliability of the proposed method are verified by measuring the external force in real time using triaxial force sensor. The multi-step forming process and the effect of external force on the roll in/out, surface wave and plastic strain of aluminum alloy sheet under the viscosity-pressure effect are studied, and the relationship between process parameters and external force is discussed. Results show that the coupling SPH-FEM model can well reflect the hemming process of curved edge structure. The normal force is about 2–3 times of the tangential force in the pre and final hemming process. Compared with the case without adhesive, the surface wave of flange part of the hemming with adhesive is slightly larger. The normal force and the tangential force increase about 90 N and 30 N respectively, when the height increases by 1 mm. It provides an important basis for the accurate control of hemming trajectory and the improvement of manufacturing quality of autobody closure panels.

Flow-induced folding in multi-scaled bulk forming of axisymmetric flanged parts and its prediction and avoidance

Flow-induced folding in multi-scaled bulk forming of axisymmetric flanged parts and its prediction and avoidance

Cold forging of a hollow flanged part by an unconventional extrusion method

This paper presents a numerical analysis of a new cold forming process for a hollow part with an external flange. The following techniques were used: forward extrusion, an unconventional method of extrusion with a moving sleeve, and upsetting in a tapered die cavity. The billet (42CrMo4 steel tube) was formed at ambient temperature. The study aimed to investigate the proposed method in terms of forged part accuracy. The following are examined and discussed: material flow, process force parameters in relation to tool strength, energy consumption of individual operations, as well as the distributions of strains, stresses, temperature and Cockcroft-Latham integrals in the produced part. The study has confirmed that hollow forged parts with external flanges of relatively large diameters and heights can be cold formed in several operations using different techniques.

A Process-Planning Framework for Sustainable Manufacturing

Process planning in manufacturing today focuses on optimizing the conflicting targets of cost, quality, and time. Due to increasing social awareness and subsequent governmental regulation, environmental impact becomes a fourth major aspect. Eventually, sustainability in manufacturing ensures future competitiveness. In this paper, a framework for the planning of sustainable manufacturing is proposed. It is based on the abstraction and generalization of manufacturing resources and part descriptions, which are matched and ranked using a multi-criteria decision analysis method. Manufacturing resources provide values for cost, quality, time and environmental impacts, which multiply with their usage within a manufacturing task for a specific part. The framework is validated with a detailed modeling of a laser machine as a resource revealing benefits and optimization potential of the underlying data model. Finally, the framework is applied to a use case of a flange part with two different manufacturing strategies, i.e., laser metal-wire deposition and conventional milling. The most influential parameters regarding the environmental impacts are the raw material input, the manufacturing energy consumption and the machine production itself. In general, the framework enabled the identification of non-predetermined manufacturing possibilities and the comprehensive comparison of production resources.

State of the art report on stub girder flooring systems

Stub girder flooring systems are a widely used system in modern steel buildings. This type of system is a composite flooring system consisting of a continuous steel beam and a reinforced concrete slab set apart by a series of short, and usually wide, flange parts known as stubs. While many studies and research have been conducted on this system in steel-concrete composite structures, comparable comprehensive research has not been done on Stub girder flooring system for timber construction. This study represents a review on stub girders, and focuses on experimental and analytical works in the area. Finally, pervious researches and experimental data about stub girder flooring system have been collected and summarized in a table format which has been listed parameters in the researches.

Angular Rolling of the Hollow Flanges of Pipe Joints

The paper considers a three-stage technology for angular rolling of the pipe workpiece. This technology facilitates the expansion of the range of flange parts available by eliminating a number of drawbacks of the known methods of metal forming. In the presented paper, we analyze the results of numerical calculations and experiments, as well as the effective deformation values in blank material, using computer simulation in the DEFORM-3D software package. The results of the computer simulation were reached taking into account experimental studies of the rheological properties of copper alloy L68 in the form of a strain hardening curve using the Instron-8850 complex. The results of the ratio of basic geometric dimensions expanded the range of flange parts under investigation and allowed us to consider angular rolling technology with a variable angle of inclination of the rolling roll from a three-stage perspective, especially in small-scale production.

A Coaxial Alignment Method for Large Flange Parts Assembly Using Multiple Local Images

The large flange parts in aero-engines are usually manually assembled. Collision damage caused by assembly alignment error often occurs in the assembly process, which affects the assembly accuracy and product reliability. The machine vision-based alignment methods usually achieve the high-precision measurement of the parts by obtaining the high-resolution images of the whole parts with a combination of laser distance sensors. Hence, existing methods are high costly and inefficient. In this paper, a new alignment method based on the principle of coaxial alignment for large flange parts is proposed. The proposed method first obtains multiple high-precision image pairs from the local field of views at the fitting surfaces of flanges. The clearance and bolt holes in each image pair are then extracted via edge recognition and Hough Transformation. Two optimization models are built to calculate the translation adjustment and rotation adjustment. The optimization model 1 is built with the translation adjustments of the flange as the variables and the consistency of the clearances as the objective function. The algorithm to solve the model based on the gradient-descent method is proposed. The positions of the bolt holes in the images are subsequently adjusted based on the translation adjustment, and the rotation adjustment is calculated by solving the built optimization model 2. The experiments show that the proposed method can be applied to the assembly process of large flange parts, and the visual servo control model based on this method also has good stability.

Numerical analysis of a two-stage forming process for a hollow part with external flange

This paper presents the results of a numerical analysis of a two-stage forging process for producing a hollow part with an external flange. The numerical analysis was performed via the finite element method using Deform-2D/3D. The analysed case included a cold forming process. The billet was a tube made of a low alloy steel grade 42CrMo4 with its flow curve described by a constitutive equation. The forming process involved the use of two operations: extrusion and forging in a tapered die cavity. The objective of the study was to determine whether the proposed forming technique could be used for production of hollow flanged parts. The kinematics of material flow, distributions of effective strains and the Cockcroft–Latham ductile fracture criterion, as well as force parameters were examined. The conducted research confirmed the correctness of the proposed method.

A comparative analysis of a four-stage and five-stage cold forging of a hollow element

The paper presents the results of a computer simulation of the process of cold forging of a hollow element with an outer flange. Computer testing was conducted in DEFORM 2D/3D using the calculation module 2D. A tube-shaped billet, made of 42CrMo4 grade steel and the inner diameter of Ø45mm, wall thickness 8 mm and length 193.5 mm was used. The analysed process was conducted in two variants. The first one was conducted in four stages, with the first two stages consisting of upsetting the flange part and the next two stages forging on cones. In the second variant, an additional stage of forging on cones was performed, aiming at elimination of the folding on the inner wall of the forging. An analysis of the technology was conducted on the basis of distributions of effective strain, values of the Cockcroft-Latham fracture criterion and progresses of the forming force. On the basis of the research conducted, it was claimed that the five-stage forging process is more favourable.

Numerical Analysis of a Six Stage Forging Process for Producing Hollow Flanged Parts from Tubular Blanks

Numerical Analysis of a Six Stage Forging Process for Producing Hollow Flanged Parts from Tubular Blanks