Pipe Support Research Articles

Attenuation properties of a meta-pipe: Analytical, experimental, and numerical prediction

Flexural vibration characteristics of a meta-pipe are investigated in this paper. Initially, the metamaterial piping system consisting of a homogeneous pipe and periodic flexible supports is designed. Subsequently, the dispersion relationship which is a function of the wavenumber and the frequency is derived employing the transfer matrix method and Bloch’s theorem. The designed system reveals a zero-frequency stopband and a wide passband in the examined frequency range, which are verified by both experimental and numerical results. To enhance the performance of this system, it is essential to effectively control the obtained passband. For this, a single-degree-of-freedom localized resonator is designed, which is subsequently installed at the center of each unit-cell of the pipe. The dispersion properties of this system are first evaluated analytically and then validated using experimental and numerical methods. Finally, the effect of pipe system parameters and resonator properties on the stopband characteristics is studied in depth. It was observed that the stopband properties can be effectively tuned by appropriately designing the piping system and resonators. The results presented in this study offer valuable insights into the propagation characteristics of flexural waves and the strategies devised for controlling vibrations in pipes.

Comparative Analysis of Water Hammer Performance in Different Pipe Parameters with FSI

Water hammer (WH) is a critical phenomenon in fluid-filled piping systems that can lead to severe pressure surges and structural damage. The characteristics of the pipe material, geometry, and support conditions play a crucial role in the fluid–structure interaction (FSI) during WH events. This study investigates the impact of various pipe parameters, including material, length, thickness, and diameter, on the WH behavior using an FSI-based numerical approach. A comprehensive computational model was developed based on the algorithm presented in Delft Hydraulics Benchmark Problem (A) to simulate the WH phenomenon in pipes made of different materials, such as steel, copper, ductile iron, PPR (polypropylene random copolymer), and GRP (glass-reinforced plastic). This study examines the influence of pipe parameters on WH performance in pipelines, utilizing FSI to analyze the phenomenon. The results show that the pipe material has a significant influence on the pressure wave speed, stress wave propagation, and the overall system response during WH. Pipes with lower modulus of elasticity, such as PPR and GRP, exhibit lower pressure wave speeds but higher stress wave speeds compared with steel pipes. Increasing the elastic modulus, pipe wall thickness, length, and diameter enhances the pipe’s stiffness and impacts the timing, magnitude of pressure surges, and the likelihood of cavitation. The findings of this study provide valuable insights into the design and mitigation of WH in piping systems.

Proposal of a Nonlinear Spring Model on Piping Support Structures for an Elasto-Plastic Response Analysis Method

Abstract In probabilistic risk assessment against earthquakes (seismic PRA) for nuclear power plants, the development of a realistic response analysis method for the fragility assessment of piping systems considering input seismic motions exceeding design assumptions is one of the important issues. Usually, piping systems exhibit complex three-dimensional shapes. The arrangement and stiffness of the piping support structures significantly affect the response characteristics of the entire piping system. Therefore, it is necessary to develop a realistic response analysis method of piping systems including piping support structures. In this study, a method for modeling the elasto-plastic hysteresis characteristics of piping support structures is developed to establish a seismic response analysis method of piping systems including piping support structures. First, we formulate an elatsto-plastic spring model that can express the elasto-plastic hysteresis characteristics of a piping support structure. Subsequently, we perform a simulation analysis for the loading test of a piping support structure using this model. As the analysis results and test results were in good agreement, we confirmed the effectiveness of the formulation of the model. The main contents, such as the formulation of the elasto-plastic spring model, the simulation analysis of the loading test, and the comparison between the analysis results and the test results, and the results of this study are reported in this paper.

Numerical examination on seismic response behavior of a piping system considering the plastic deformation of supports

A previous study proposed a passive safety structure to mitigate severe damage to crucial components under the beyond design basis event (BDBE). To examine the applicability of this concept to the piping system, the effect of the elastic-plastic behavior of the piping support structure on the seismic response of the piping system was investigated through elastic-plastic time history response analyses on a piping system model with multiple support structures. The numerical analyses considered the elastic-plastic behavior of supports and/or the inelastic characteristics of pipe material. The analysis results confirmed that the response of the piping system can be suppressed by adequately introducing the inelastic behavior of support structures. The results show the possibility of realizing of passive safety structure in piping systems and addressing some issues, such as changing vibration modes due to the elastic-plastic deformation of the support or the order of generation of inelastic behavior of pipe material and supports.

A CFD-DEM investigation into hydraulic transport and retardation response characteristics of drainage pipeline siltation using intelligent model

Siltation of drainage pipelines is a major disaster-causing factor in urban flooding. Owing to critical bed shear stress and the possibility of settlement at the bottom of pipes, there are significant nonlinear differences in the hydraulic transport and retardation response characteristics of siltation particles under different initial flow velocities, siltation degrees, and siltation lengths. Studies on siltation in drainage pipelines lack a comprehensive understanding of the intricate coupling dynamics between siltation particles and water flow, and the regularity governing the siltation transport behaviour under varying water flow conditions remains unclear. To solve these problems, this study constructs computational fluid dynamics and discrete element (CFD-DEM) coupling method and adaptive penalty model for pipeline deposition based on probabilistic settlement function, adaptive genetic algorithm, and bidirectional long short-term memory neural network (PSF-AGA-BLSTM). A three-dimensional transient hydraulic model of pipeline siltation was adopted to clarify the critical bed shear stress of the silt particles, after which an adaptive genetic algorithm with a probability settlement function as fitness was constructed to generate a numerous silt particle sample sets with settlement result labels. Adaptive genetic algorithms were combined with bidirectional long short-term memory neural networks to establish a spatiotemporal adaptive penalisation mechanism for pipeline silt particle transport. The simulation model based on PSF-AGA-BLSTM and CFD-DEM was analysed using simulation and scale tests and was found to have strong robustness and reliability. The results showed that the effects of siltation degree, flow rate, and siltation length on the transport of silt particles were all non-negligible; when the siltation degree exceeded 0.2, the siltation degree had a more significant effect on particle transport than siltation length and flow rate. The transport of silt particles occurred in two phases, rapid growth and steady growth under erosion by water flow. The rate of change in silt length accounted for up to 45% of the reason for silt nudging and silt spreading. The study clarified the hydraulic transport law of silt particles and analyzed the effect of different influencing factors. These efforts provide technical support for subsequent pipe cleaning and maintenance as well as flood prevention and mitigation.

Experimental and mechanistic investigation on the plastic anisotropic deformation behavior of α-phase titanium alloy Ti-2Al-2.5Zr

Ti-2Al-2.5Zr is widely used in piping and structural support applications, however, the rolling forming process results in anisotropic deformation during service. This behavior has implications for the manufacturing processes and structural safety assessments in engineering applications. In this study, the plastic anisotropic deformation behavior of a rolled Ti-2Al-2.5Zr plate was investigated using uniaxial tensile tests along the transverse, normal, and 45° directions. Acoustic emission, electron backscatter diffraction, and scanning electron microscopy methods were used to investigate dislocation slip and twinning mechanisms. The results indicated that different microscopic deformation mechanisms caused the significant macroscopic anisotropy of Ti-2Al-2.5Zr. The primary mechanisms involved were prismatic <a> slip, pyramidal <c+a> slip, and {10-12} extension twinning. The stress direction determined the influence of each of these mechanisms during the yielding and plastic deformation phases. Application of the visco-plastic self-consistent model established the relationship between the macroscopic mechanical responses and microscopic deformation mechanisms. It was revealed that Ti-2Al-2.5Zr achieved its optimum strength when the initial texture aligned most of the grain c-axis at angles ranging from 30° to 50° relative to the deformation direction. This finding provides a direction for the texture design of Ti-2Al-2.5Zr in engineering materials.

“I think I exactly know why I am here”: what do mature female students tell us about their experiences on a foundation programme

ABSTRACT The concept of the ideal student is one that has generated much research across many disciplines across the globe and continues to stimulate debate about teaching and learning within higher education. This paper explores the concept of the ideal student in relation to the experiences of mature female students enrolled onto a Foundation Programme in Business and Management. Although some Foundation Programmes are intended to recruit international students, most are conceived for school-leavers who are deemed to be the ideal cohort for this programme by the university. As such, there exists the potential for a disconnect between the concept of an ideal student which is generally associated with an implied curriculum model and the experiences of mature students. This paper explored the experiences of mature female students on a Foundation Programme at an English Business School that prepares students for undergraduate study. The research involved interviews with five mature female students, three of whom are mothers. The findings were analysed using Interpretative Phenomenological Analysis and challenges the concept of the ideal student as useful theoretical model upon which to construct the curriculum. This paper also conceptualises the mature student learning journey through the PIPE support model.

A soft ground micro TBM’s specific energy prediction using an eXplainable neural network through Shapley additive explanation and Optuna

In tunnel construction, efficiently predicting the energy usage of tunnel boring machines (TBMs) is critical for optimizing operations and reducing costs. This research proposes a novel method for predicting the specific energy of micro slurry tunnel boring machines (MSTBMs) using an explainable neural network (xNN) that leverages operator-monitored data. The xNN model provides transparency and interpretability by integrating the Shapley additive explanation (SHAP) technique, enabling tunneling engineers and operators to gain valuable insights into the prediction process. Extensive data from MSTBM umbrella pipe support excavation are the foundation for training, testing, and unseen data in the xNN model. The specific energy formula derived from the operational parameters of the MSTBM defines the dependent variable for the xNN model. The test dataset evaluates the model’s performance with an R² of 98.7%, an MSE of 2.40, and an MAE of 0.003, demonstrating its accuracy and reliability. Ten percent of the dataset was reserved as unseen data to assess the model’s generalization capabilities. Upon evaluation, the model achieved an R2 value of 89%, an MAE of 0.01, and a root mean squared error (RMSE) of 0.01. The xNN empowers operators to optimize operational parameters and promote more efficient and sustainable tunneling practices by identifying influential factors affecting energy consumption through its interpretable nature. This research has significant implications for the future of underground construction, paving the way for improved resource management.

Degenerated High-Energy Piping Supports of Thermal Power Plants

High-energy piping systems of power plants, such as Main Steam (MS) pipes or Hot Reheat (HR) pipes, operate at high temperatures and high pressure at base and cyclic loads. In the event of transient conditions, a pipe can be deflected dramatically and cause high stress in the pipe, leading to the failure of the piping system. Pipe hangers/supports are vital in maintaining the forces and stresses of the piping system within the allowable limits by allowing sufficient pipe movement from cold to hot conditions and protecting the piping system from operation transient loads such as steam hammer and water hammer events. Thus, the pipe hangers and supports shall be inspected regularly to ensure their functionality. This paper presents examples of common issues found in degenerated pipe hangers/supports in power plants. The pipe support site inspection generally found deviations in pipe travel, which were not as expected by design. Design reviews have shown that the design travel of pipe support can differ from those found on pipe support nameplates, and the deviation can be as much as 74%. The actual load of pipe support can deviate as much as 18% from the design load and requires rectification as undesirable high stresses can be developed over time if it is left unattended. Pipe hanger/support inspection data can be used in further assessment, such as piping structural analysis. Deteriorated or degenerated pipe supports shall be identified, prioritised for further assessment, and monitored regularly as part of a strategy and initiative to ensure total plant safety management, with the aim to minimise the risk of premature and catastrophic failures.Keywords: degenerated, inspection, pipe hanger/support, piping systems, power plant, walk-down

Study on the Ultimate Load-Bearing Capacity of Disc Buckle Tall Formwork Support Considering Uncertain Factors

Disc buckle steel pipe brackets are widely used in building construction due to the advantages of its simple structure, large-bearing capacity, rapid assembling and disassembling, and strong versatility. In complex construction projects, the uncertainties affecting the stability of disc buckle steel pipe support need to be considered to ensure the safety of disc buckle steel pipe supports. A surrogate model based on a deep neural network is built and trained to predict the ultimate load-carrying capacity of a stent. The results of the finite element model calculations are used to form the sample set of the surrogate model. Then, we combined the computationally efficient DNN surrogate model with the Monte Carlo method to consider the distribution of the ultimate load capacity of the disc buckle bracket under the uncertainties of the bracket node pin wedge tightness, the wall thickness of the steel pipe, and the connection of the connecting wall member. At the same time, based on the DNN model, the SHapley Additive exPlanations (SHAP) interpretability analysis method was used to study the degree of influence of various uncertainty factors on the ultimate bearing capacity of the stent. In practical engineering, the stability analysis of a disc buckle tall formwork support has shown that a surrogate model based on a deep neural network is efficient in predicting the buckling characteristic value of the support. The error rate of the prediction is less than 2%. The buckling characteristic values of the bracket vary in the range of 17–25. Among the various factors that influence the buckling characteristic value of the bracket, the joint wedge tightness has the greatest impact, followed by the bottom and top wall-connecting parts.

Investigation on damage evaluation index with ductility factor based on simulation analysis for loading test of piping support structure

Investigation on damage evaluation index with ductility factor based on simulation analysis for loading test of piping support structure

Conceptual design and feasibility for an effective elastic-plastic pipe support on seismic response reduction

Conceptual design and feasibility for an effective elastic-plastic pipe support on seismic response reduction

Analisis Tegangan pada Jalur Pipa dengan Pemindahan Penopang Akibat Longsor

Landslide that has done in the Chevron, Minas oil field area on 4A-54 pipeline section, resulted the failure at one of pipe supports of 12in and 8in pipe diameter. The Action is planned to remove pipe support number 2 which affected a landslide, and move pipe supports number 1 and 3 that is closer to pipe support number 2. For this reason, action is being taken to redesign the piping system so that the pipe line can function safely. Allowable piping design criteria are used based on the maximum distance between pipe supports and maximum stress based on ASME B31.3 standards not greater than 20,000 Psi. Based on the calculation results, the allowable maximum distance between 12 in pipe supports is 16.064 m. Base on stress simulation, the maximum combined tension and torsion stress on the pipeline at that distance is 17606.44 Psi, 12% less than the allowable stress. The combine stress in the pipe produce displacement of pipe in the x-axis direction of 0.074 m and -0.95o.

Design of a low stiffness magnetic support for the carbon fiber pipe under low-frequency vibration and impulse

Carbon fiber optical arms are highly sensitive to vibration disturb, and external vibrational excitation can significantly degrade the accuracy of the optical path. Firstly, this paper proposes a carbon fiber optical arm pipe magnetic support system for low-frequency and impulse vibrations. The overall stiffness of the magnetic support is reduced by the cooperation of mechanical springs with positive stiffness and magnetic springs with negative stiffness. Secondly, based on analytical calculations of magnetic forces and finite element simulations, a comprehensive dynamic model of the system is established and solved using the Runge–Kutta method. Finally, an experimental platform for the equipment is set up, and both frequency sweep response tests and impulse vibration response tests are conducted on the system. The results demonstrate that the proposed magnetic support with low stiffness effectively reduces the interference of low-frequency vibrations on the supported carbon fiber pipe.

Detection and Measurement of Pitting Corrosion using Short Range Guided Wave Scanning

Short range guided wave scanning is an inspection method enabling an indirect, quantitative measurement of remaining pipe wall thickness. It has seen widespread industrial use as an inspection solution for corrosion under pipe support (e.g. [1]). Pitting corrosion represents a significant challenge in industrial pipelines and its presence complicates short range guided wave scanning analysis as the wavelength used for inspection is larger than the diameter of small pitting-type defects. This work investigates the reflected signal from pitting corrosion, both in isolation and in the presence of larger corrosion patches, to improve the understanding of the complex signals received. This work provides the foundation and guidance for analysis techniques used in guided wave scanning. To achieve this a series of representative pitting defects with varying diameter and depth have been investigated using explicit finite element modelling. It is shown that using currently established analysis techniques, the pit depth can be quantified for pitting with a diameter larger than approximately 13 mm. Smaller diameter pitting may only be qualitatively detected at this time due to mode conversion occurring at the defect, which obscure features that are used to provide quantitative analysis of the defect depth. Quantitative sizing of defects where pitting is present will require further investigation.

Cumulative Fatigue Damage of Small-Bore Piping Subjected to Flow Induced Vibration

The structural fatigue of a vertically oriented small-bore connection due to flow induced turbulence emanating from an upstream piping manifold is experimentally investigated. Dynamic strain measurements are taken at two perpendicular locations on a small-bore connection and the method of rainflow counting is used to determine the cumulative damage incurred. A number of factors is investigated and their influences on the cumulative damage are explained. These include the effects of (1) single phase and multiphase flow, (2) the upstream flow path through the manifold, and (3) steady-state and transient conditions. From the experimental analysis, key observations that may be useful to piping designers and engineers are reported. For instance, for single-phase water, the largest bending stresses are due to the out-of-plane vibration of the small-bore piping, whereas the pulsating characteristics of the single-phase air and multiphase flow result in significantly larger in-plane bending stresses. It is also observed that under certain manifold outlet conditions, transient effects upon pump start-up can produce more than 300 times the cumulative fatigue damage compared to steady-state operation. As part of this study, the finite element method is also used to investigate the influence of piping support stiffness on the fatigue life of a small-bore connection. Through a series of parametric analysis, it is demonstrated that there exists a minimum support stiffness for which the fatigue life of a small-bore connection excited by flow-induced vibration, achieves its upper bound value.

Research on Crossing-Pipe Support Structure Defect Detection of EMAT-Excited CSH Wave

A circumferential shear horizontal (CSH) guide wave-detection method using a periodic permanent magnet electromagnetic acoustic transducer (PPM EMAT) was proposed to solve the defect detection located at the inside of the pipe welded by supporting structures. Firstly, a low-frequency CSH0 mode was selected to establish a three-dimensional equivalent model for the defect detection to cross the pipe support, and the ability of the CSH0 guided wave to propagate through the support and weld structure was analyzed. Then, an experiment was used for the further exploration of the influence of different sizes and types of defects on detection after using the support, as well as the ability of detection mechanism to cross different pipe structures. The results show that both the experiment and the simulation received a good detection signal at 3 mm crack defects, which proves that the method can detect the defects by crossing the welded supporting structure. At the same time, the support structure shows a greater impact on the detection of small defects than the welded structure. The research in this paper can provide ideas for guide wave detection across the support structure in the future.

Construction Technology of Mixed Support for Starting Section of Concrete Box Arch

In the construction of the starting section of a concrete arch bridge spanning ravines or deep water, technical problems such as the inability to adopt full-stent construction, resulting in low construction efficiency. In response to this problem, this paper relies on the Shatuo Bridge in the deep-water area near cliff and proposes the use of a steel pipe support and a hybrid bracing technology to construct the starting section of the arch bridge, that is, using a steel pipe bracket near the arch foot. Cast-in-situ construction and horizontal force components are provided by diagonal cables and steel beams are embedded in the arch seats to balance the horizontal loads on the supports. The rest of the beam sections that cannot be erected with steel pipe supports are constructed by using inclined anchors. The practice shows that this technology successfully overcomes the limitation of the construction work space, and achieves the purpose of reducing costs and shortening the construction period. And the method can provide reference for the construction design of similar structures.

Research and Example Verification on Stability Coefficient of Vertical Bar of Fastener Steel Pipe Support

The calculation method of steel pipe support in current specifications is not uniform, and it is unsafe to directly apply the stability coefficient of the vertical bar in the current code, which leads to frequent safety accidents of fastener steel pipe supports. Through the field statistics of the initial defects of the steel pipe, it is found that the initial bending values of the 3 m and 6 m steel pipes with the largest size are larger in L/400. The stability coefficient table is obtained by taking the initial bending of L/400 as the initial defect, which is 43.15% smaller than the stability coefficient given by the specification. Through the comparative analysis of the actual engineering monitoring results, the calculation results of the original specification and the calculation results after the correction of the stability coefficient, it is concluded that the stress calculated by the stability coefficient proposed in this paper is similar to the actual monitoring results of the project and is greater than the stress of the vertical rod calculated by the stability coefficient of the original specification. It is suggested that the corrected stability coefficient should be applied to the actual project.

Strength evaluation of support frame of the low level liquid effluent pipes of nuclear plant

Disposal of low level radioactive liquid effluents of nuclear plant into the sea is carried out through carbon steel pipes inside a guard pipe. The treated effluents are discharged inside the sea beyond breaker zone through two disposal pipes. The disposal pipe discharges the treated effluent to two numbers of 1 m diameter pipe which goes down till sea bed. This guard pipe should be supported on top of the jetty against wind, wave, and dead loads. This study is intended to cover the design adequacy and material selection of the liquid discharge piping support configuration. Material and coating requirements of the support frame is chosen after careful evaluation of the prevailing saline environment and economic consideration. Elastomeric bearing provides necessary support & firm adherence of the support arrangement to the erected pile cap. Elastomeric bearing are easy to install and offer low maintenance. The support frame is checked for dead load, pipe load, live load, wind load, wave ¤t loads, and seismic loads. Wave and current loads were calculated based on Morison semi empirical equation. Linear elastic structural analysis of the support frame was carried out. This article provides insight to the materials used in supporting this pipelines and the basis behind the material selection. After material selection, strength evaluation of the structure is elaborately carried out for all the loads. Indian standards and API recommended practice were adopted for the strength assessment of the structure. Support arrangement is formed using trusses at different levels, spandrel girders and hangers connecting the spandrel girders. All the stresses for structural arrangement for liquid discharge pipe support are checked and found within acceptable limits.