Burst Pressure Research Articles

Evaluation of intestinal wall closure using vessel-sealing technology versus conventional closure: an in vivo study.

Anastomotic leakage is a major postoperative complication of colorectal surgery. LigaSure™ is used commonly for vessel-sealing, but its use for intestinal anastomosis or closure, particularly the healing process, is underreported. We conducted this study to evaluate the feasibility of using LigaSure™ for intestinal wall closure, compared with hand-sewn methods. We performed intestinal wall closure of the cecum in rat laparotomy procedures, dividing subjects into a LigaSure™ group (LS) and a hand-sewn group (HS). We compared operation times, tissue structure changes, and pressure resistance from immediately post-operatively to postoperative day (POD) 14. No postoperative dehiscence or mortality occurred in either group. The LS group required significantly less closure time (113s) than the HS group (321 s, p < 0.001). The adhesion rates for a midline incision were not significantly different between the groups (LS: 26.7% vs. HS: 6.7%; p = 0.142), with adhesions at the closure site seen in all subjects. The LS group had a lower burst pressure than the HS group until POD 3, with no significant differences thereafter. Structural continuity was established by POD 5 in both groups. LigaSure™ provides effective intestinal wall closure with a more distinct healing process than with hand-sewn methods, suggesting the potential for staple-free anastomosis.

Effect of burst pressure and vented area on vented hydrogen explosions

Effect of burst pressure and vented area on vented hydrogen explosions

Effects of Ethanol Locks on Burst Pressure for Small Caliber Nonpower Injectable Peripherally Inserted Central Catheters.

Effects of Ethanol Locks on Burst Pressure for Small Caliber Nonpower Injectable Peripherally Inserted Central Catheters.

Optimizing performance of hybrid fiber reinforced overwrapped pressure vessel

Composite overwrapped pressure vessels (COPVs) offer significant weight advantages over traditional all-metal vessels particularly in industries like aerospace, automotive and pharmaceutical, but pose unique challenges in mechanical design, fabrication, and testing. Despite their benefits, COPVs are susceptible to stress rupture failure, which can lead to catastrophic consequences during operation. This failure mode is not fully understood, with burst pressure-induced extreme stress concentrations and dynamic loading primarily contributing to rapid deformation and strain. To address these concerns, a comprehensive investigation was conducted, focusing on optimizing and examining the effects of optimum winding angle and lay-up pattern configuration on burst pressure in vessels under internal pressure. Finite element modeling analyzed the burst pressure behavior of COPVs with a 4 mm thick aluminum core cylinder and varying layers of carbon/fiber epoxy, each with a constant thickness. ABAQUS composite modeler generated 18 COPV models with carbon fiber/epoxy plies, ensuring uniform thicknesses while exploring different fiber orientations. The effects of ply stacking sequence were analyzed through finite element analysis for all models, comprising varying layers with uniform thicknesses. Attention was paid to failure criteria, methodically evaluating the burst strength of the Al/CFRPC COPVs This exhaustive analysis yielded an optimal COPV design profile characterized by a precisely calibrated ply stacking sequence of [24.50, −24.50] PP winding pattern and six (6) arranged layers. The stress-strain distribution analysis of the Composite Overwrapped Pressure Vessel (COPV) revealed both a uniform distribution of stress across its surface and extreme stress concentration, particularly peaking towards the polar boss region. This concentration is discernible due to variations in ply thickness induced by the overwrapped fiber orientation. This investigation provides valuable insights for optimizing COPV design and enhancing its performance and reliability in various applications.

Structural design of a balanced cone-spherical fiber-reinforced rubber hose

This article focuses on the optimal structural design of a balanced cone-spherical fibre-reinforced rubber hose (RH). Combined with deformation characteristics of the conical RH, the cone-spherical RH is improved based on the spherical RH. Then the mechanical model of balance performance, stiffness and burst pressure for the cone-spherical RH is constructed. The structural optimization design of double cone-spherical RHs is conducted to further reduce the stiffness of the RH. The model is applied to large-sized RH. Eventually, in the optimization case of this article, the double cone arc-shaped structure has the smallest stiffness. Compared to existing single curved RHs, the stiffness has been reduced by 53%. The correctness of the theoretical model is verified through experiments.

Structural integrity assessment of pipe elbows: Burst test and finite element analysis

In this study, the failure pressures of pipe elbows were compared with those predicted using Level 3 numerical assessment method (Finite Element Method). Four 90-degree pipes elbows representing a pristine pipe, a pipe with a single corrosion defect, a pipe with longitudinally aligned interacting defects, and a pipe with a circumferentially aligned interacting defects, were subjected to internal pressure based on the ASME B31.3–2012 Burst Test standard until failure. The Sch-80 pipes were made of ASTM A234 WPB steel with a wall thickness and bending radius of 12.7 mm and 305 mm respectively. The corrosion defects were simulated on the exterior surface of the pipe elbows using computer numerical control (CNC) machine to generate a machined version of the corrosion defect. The results revealed that corrosion defects significantly reduce the burst pressure of pipe elbows, with longitudinally aligned interacting defects causing the largest reduction of 20.9 % compared to pristine pipe. The comparison between the Level 3 numerical assessment method and burst test showed close agreement with a maximum difference of 4.79 %, confirming the accuracy and reliability of the numerical method.

Consistency analysis of burst pressure in corroded pipelines

Abstract Due to the influence of the working environment and transport medium, corrosion defects inevitably occur on the inner and outer walls of natural gas pipelines. Scholars often studied the influence of internal and external corrosion defects on pipe burst pressure based on finite element method and experiment. However, it is not clear whether internal corrosion defects and external corrosion defects are consistent in burst pressure of pipelines. For this reason, this paper establishes the internal and external corrosion defect model of the pipe. Then, the burst pressures of pipelines with internal corrosion defects are compared with that with external corrosion defects. Finally, a burst pressure equation is proposed for the pipelines with internal corrosion defects and external corrosion defects. It was found that the burst pressure of the natural gas pipeline with internal and external corrosion defects was consistent. It provides a new idea for the establishment of a unified model to predict the burst pressure of corroded pipelines.

Successful Coronary Interventions with the Ingenious Vector\(\circledR\) Balloon in Chronic Total Occlusion (CTO): A Preliminary Study

Aims: To assess the safety and plausibility of successful coronary interventions in Chronic Total Occlusion (CTO) with the innovative Vector\(\circledR\) balloon through balloon-assisted crossing technique. Study Design: Observational, prospective study. Place and Duration of Study: Department of Cardiology, King Edward Memorial Hospital and Seth G. S. Medical College, Mumbai. The study was carried out between the months of March and June, 2024. Methodology: A total of 20 patients were included in the study. All patients with chronic coronary syndrome were being planned for Percutaneous Coronary Intervention (PCI) for CTO. During PCI, the standard protocol of intervening CTO lesions was followed. When the operator was not able to cross the lesion with standard CTO guidewires, Vector\(\circledR\) balloon-assisted crossing was planned. This technique was used in a total of seven (35%) patents. Success was defined as the possibility of advancing the guidewire further to the target lesion and being able to deploy a drug eluting stent. Safety was assessed as reporting complications like kinking or rupture of the balloon shaft, loss of balloon inside the guide or the coronary artery and the balloon burst rate after inflation exceeding the Rated Burst Pressure (RBP) according to the manufacturer’s reference table. Results: The mean age of the patients was 58.1 ± 3.6 years. The balloon-assisted crossing was successful in all seven patients. The most commonly used diameter of the balloon was 1.25 mm (42.85%). Conclusion: The novel Vector\(\circledR\) balloon catheter showed excellent result when deployed to treat the CTO after the usual strategy of guidewire escalation had failed. The proximal shaft with polytetrafluoroethylene (PTFE) coating brings the flexibility to navigate complex and tortuous vascular pathways with ease due to its laser welded core-wire. A study with a larger sample size and a comparator arm would rather clarify if such a balloon-assisted crossing technique in CTO would decrease the need of costly devices like double lumen microcatheters.

Prediction of composite pressure vessels’ burst strength through machine learning

In Hydrogen Fuel Cell Electric Vehicles, hydrogen is stored as compressed gas in tanks made from carbon fiber composite. Tanks are designed to withstand 2.25 times the nominal working pressure. If low variability in tank strength can be demonstrated, this margin of safety could be reduced. This requires accurate prediction of the strength of the vessel and quantification of its uncertainty. In this work, several composite pressure vessels are manufactured using filament winding, and the parameters that control the winding and curing recorded as time signals. Process parameters include fiber tension, winding speed, liner pressure, fiber volume fraction, winding time and curing pressure. The vessels are tested for burst pressure. Several configurations are defined, where each manufacturing parameter is changed. The recorded manufacturing data are fed to machine learning(ML) algorithms and trained to predict the vessel’s burst pressure. These ML algorithms include neural networks, Gaussian process regression GPR, Kernel Principal Component Analysis-Lasso (kPCA-Lasso), and an Ensemble regressor. The KPCA-Lasso and GPR models show good correlation. The Ensemble regressor yields better results by combining the KPCA-Lasso and GPR models. The study demonstrates the potential of ML algorithms in predicting the burst pressure of carbon fiber vessels from the monitored manufacturing data.

Data augmentation using SMOTE technique: Application for prediction of burst pressure of hydrocarbons pipeline using supervised machine learning models

Accurate burst pressure prediction is critical for ensuring oil and gas pipeline safety, guiding maintenance decisions, and lowering costs and risks. Traditional methods have limitations, including high experimental costs, conservative empirical models, and computationally expensive numerical algorithms. Machine learning (ML) models have supplanted traditional methods in recent years. However, small and imbalanced datasets are the big challenge to build a ML model that can generate more accurate results. Moreover, the lack of generalization in ML models trained on a dataset of pipelines with specific material grids prevents them from producing superior results on other pipeline types. First, FEA was used to make a dataset. Then, a new way to improve machine learning (ML) model generalization for burst pressure prediction is suggested: combine publicly available datasets of different pipeline specifications. In this combined dataset, some pipelines have a higher number of data samples, and some have fewer, which causes a class imbalance issue. The Synthetic Minority Oversampling Technique (SMOTE) technique was applied to address the issue of class imbalance. The performance of various ML models, Extra Trees (ET), Extreme Gradient Boosting (XGBR), Random Forest (RF), Light Gradient Boosting Machine (LGBM), and Decision Tree (DT), was evaluated to validate the model's prediction and generalization on pipelines of various material grids. Results show that all the selected ML models produced high R-squared, i.e., >0.95, on balanced data compared to the imbalance dataset. These results show that SMOTE-based augmentation is a beneficial way to fix dataset imbalance and make ML models better at predicting burst pressure in oil and gas pipelines.

Failure monitoring and classification from acoustic emission tests on impact-damaged hydrogen composite pressure vessels

Composite overwrapped pressure vessels (COPV) for hydrogen will play an important role in emission free mobility and energy storage. The DELFIN project (2018 – 2022) was set up with the goal of developing improved COPVs that are lighter, cheaper and more durable. A key aspect of this project was to conduct full-scale impact tests with different gas pressure levels that were used to evaluate the vessels’ crash performance and to verify numerical impact simulations. These tests were followed by controlled pressure experiments until the burst pressure was reached. The procedure was monitored with acoustic emission testing (AT) and subsequent computer tomography (CT). The residual COPV stability and the AT results are compared to different scenarios regarding the impact energies and impact angles. The event localization from AT shows a clear correlation of the emitted energy with the damaged areas. We classify the recorded signals into groups that can be related to the failure mechanism and compare those to the pressure evolution before failure of the COPV. All tests indicate that large impact energies lead to a significant reduction of the burst pressure of COPVs, whereas a higher internal pressure can have a stabilizing effect that reduces the damaging effect.

Damage-tolerance design for composite high-pressure hydrogen vessels when AE testing is applied

An approach was proposed to design high-pressure composite hydrogen vessels for fuel cell vehicles with damage tolerance. In addition, a stacking-sequence optimization method was developed, which was built upon the damage tolerance design. A no-growth approach, damage categorization, and residual strength requirements were proposed for the damage-tolerance design method for highpressure hydrogen vessels, which were implemented in the damage-tolerance design method for composite aircrafts. The initial burst pressure was set at 180% of normal working pressure (NWP) assuming that the structural health monitoring (SHM) system with acoustic emission (AE) testing would immediately detect the occurrence of fiber breakage. Stacking-sequence optimization was then conducted to minimize vessel thickness and meet the residual strength requirements. The results show that the thickness of the vessel can be reduced by introducing a damage-tolerant design. Moreover, the proposed method for an optimal design based on the damage-tolerance design method is effective.

Strength Performance Evaluations of Vehicle Cylindrical LPG Tanks

This study aims to examine and compare the strength performances of vehicle cylindrical liquefied petroleum gas (LPG) tanks produced and used in Turkey, taking into account European and Turkish Standards. The LPG tanks were subjected to burst and fatigue tests to explore their burst pressures and fatigue performances using both experimental and computer aided techniques. To investigate the strength of the tanks, a universal test bench was developed and calibrated for use in both burst and fatigue tests. The obtained experimental results in terms of burst and fatigue failure locations for each brand of tank are compared with the results obtained using finite element based simulations. Visual solid models in 3D were drawn in SolidWorks and then ANSYS software was used to perform Finite Element Analysis (FEA) simulations on those LPG cylinders to obtain the results, such as stresses, deformations, burst and fatigue failure locations. As a result of this comparison, it has been observed that some brands of cylindrical LPG tanks are more durable and safe for use in vehicles. Since the same standard requirements and the same commercial material are used in LPG tank production, it is revealed that some companies need to reconsider their design, manufacturing and especially welding processes. The results of this independent and objective study can also be used as a warning for LPG tank manufacturers and as a guide for their customers in choosing a safe product.

Biocompatibility and Haemocompatibility Assessments of RBC with Polymeric Coated Cardiac Stent.

The current investigation was conducted to evaluate the biocompatibility and hemocompatibility of polymeric-coated cardiac stents. Coronary stents are typically small wire mesh tubes that are used to open arteries that are obstructed over time as a result of the buildup of fat, cholesterol, or other materials. A 10 milliliter isolated blood red blood cell was obtained using the Prozeta cobalt chromium coronary stent, which had the following specifications: stent length = 18 mm, strut thickness = 0.065 mm, expansion range = 2.25 mm to 4.00 mm, and burst pressure = 6ATM. Using an R&amp;D coating equipment, polyethylene glycol (PEG) polymers were applied to the coronary stent. Assessments of the polymeric-coated cardiac stent’s biocompatibility and hemocompatibility were conducted using various evaluation criteria. CAD software has been used to help with the stent’s modeling. According to the supplied catalog, the strut’s thickness and width are calculated to be 0.065 mm and its length is 18 mm. The histology of RBC in an isolated sample (polymer coated on stent) found at 2000 Rx was examined using a motic microscope. Using a UV-visible spectrophotometer set to 414 wave length, a 10µg/ml solution of RBC in distilled water was scanned at 200–500 nm to measure the UV absorption maximum. The absorbance was found to be 0.8312 nm. An FTIR analysis of RBC reveals absorptions that include bending and stretching vibrations. Peak Position was discovered at wave numbers 3661.76, 1684.62, 1547.98, 1472.07, 1278.06, and 841.98. Using SEM the surface morphology of RBC was study and it was found the measurements 6.1, 4.2, 3.3, 3.2, 3.1, and 2.2 µm in diameter with standard error 0.548584. It has been determined that PEG-coated material demonstrated significant outcomes that resulted in coronary stent that was both biocompatible and hemocompatible of polymeric-coated cardiac stent, which is a step towards altering the treatment regimen.

Impact of stacking sequence on burst pressure in glass/epoxy Type IV composite overwrapped pressure vessels for CNG storage

The shift from metallic to composite pressure vessels for storing compressed natural gas (CNG) is driven by the goal of reducing environmental impact by using lighter higher-performing structures. This work focuses on enhancing the internal pressure strength of a type IV composite overwrapped pressure vessel (COPV) by optimising the stacking sequence of the overwrapping composite layers. Parametric finite element (FE) models are developed to reveal symmetry effects. In these models, both the thickness build-up and fibre angle variation at the turnaround zones are accurately modelled. Subsequently, the stacking sequence is optimised with the objective function of maximising burst strength. The parametric modelling demonstrates that representing the COPV as an axisymmetric continuum reduces computational costs in 5400× while yielding results comparable to full 3D continuum models. Experimental burst tests are carried out to validate the numerical predictions, and the difference in pressure between them is 12.6 %.

A novel framework for predicting the burst pressure of energy pipelines with clustered corrosion defects

The accurate prediction of failure pressures in pipelines containing multiple defects is important for assessing the integrity and reliability of corroded pipelines. First, the effect of the remaining defects on the failure pressure of the pipeline containing triple defects was investigated by developing the finite element (FE) model of pipelines containing triple defects. Then, to integrate machine learning method and finite element models to establish a prediction model for the interaction coefficients corresponding to combined corrosion defects. Subsequently, a framework for predicting the burst pressure of pipelines appliable to the scenario of group corrosion defects was proposed by integrating the interacting coefficient and the failure pressure of single defect. Finally, the accuracy of the model was demonstrated by the evaluation indicators and bursting experimental data of corroded pipeline containing cluster defects. The framework is expected to provide a maintenance foundation for the integrity assessment of pipelines with clustered corrosion defects.

Structural Design and Mechanical Properties Optimization of a Balanced Fiber-Reinforced Rubber Hose

This paper focuses on the optimal design of the structure of a balanced fiber-reinforced rubber hose (RH). A multi-spherical RH is proposed. Based on the grid method, the structure optimization design of single-spherical and multi-spherical RHs is performed. According to the constraints, the optimization results of the structural parameters of the RH are solved. Then, combined with the deformation characteristics of the conical RH, the cone-spherical RH is improved based on the spherical RH. The mechanical equilibrium angle and deformation expressions of the cone-spherical RH are deduced. The mechanical model of the balance performance, stiffness, and burst pressure for the cone-spherical RH is constructed. The structural optimization design of double-spherical and double cone-spherical RHs is performed to further reduce the stiffness of the RH based on the multi-spherical RH. Eventually, the correctness of the theoretical model and its optimization results is verified through experiments. The results of this research can provide reference data for future studies in related fields.

A study on the small failure probabilities of cylindrical composite hydrogen storage tanks using subset simulation

Although composite hydrogen tanks are becoming increasingly intriguing, a detailed structural reliability analysis is still lacking. The current landscape of analysis for pressurised multilayer cylinders, while rich in research, lacks tools to deal with the low probabilities of failure that govern the design of hydrogen tanks. This study presents a computational framework integrating the Subset Simulation method (SS) for assessing the failure probability of composite tanks used for hydrogen storage. To explore how randomness impacts design parameters, this study utilises a limit state equation derived from the thin-walled circumferential model of composite pressure tanks. Five random variables, each with varying coefficients of variation (COVs), are incorporated into the analysis. For comparison and validation purposes, two methods Monte Carlo simulations and FORM have been used. The analysis revealed that SS excels at estimating the low failure probabilities of composite hydrogen tanks, and showed also the feasibility and accuracy of SS in the prediction of burst pressure since good agreement was obtained between the probabilistic approach and the experimental results. Furthermore, the uncertainties related to internal pressure and composite thickness affect significantly the reliability of the structure and can lead to the shrinkage of the safety margin and the failure of the vessel.

An all-purpose method for optimal pressure sensor placement in water distribution networks based on graph signal analysis

Many researchers have addressed the challenge of optimal pressure sensor placement for different purposes, such as leakage detection, model calibration, state estimation, etc. However, pressure data often need to serve multiple purposes, and a method to optimize sensor locations with versatility for various objectives is still lacking. In this paper, a graph-based optimal sensor placement (GOSP) framework is proposed, which aims to provide a robust and all-purpose approach to identify critical points for pressure monitoring. By analysing the spatial variation frequencies of WDN pressures, the relationship between measurements and the global variation of original pressures is established. On this basis, the D-optimality criterion is adopted to formulate the objective of GOSP, which aims to maximize the information on the spatial distribution of pressures that can be obtained from measurements. The new-proposed objective ensures that the sensor locations are compatible with various application scenarios. The proposed method was applied to a real-life distribution network, and was compared with other optimal sensor placement methods oriented towards burst detection and pipe roughness calibration. Based on comparative studies in different scenarios including unknown pressure estimation, burst detection, and model calibration, the effectiveness and robustness of the proposed method have been proved.

Subset simulation based simplified approach for pipeline with multiple irregular corrosion defects in time-dependent reliability analysis

Pipeline system plays an important role in the natural gas and petroleum transportation, and it is widely employed in the engineering application. However, the pipeline system is subjected to corrosion given the industry environment condition, or soil condition when it is buried. In this case, it is important to assess the remaining life of corroded pipeline. Consequently, it is important to predict the failure probability considering the corrosion growth over time and operating pressure. Nevertheless, the prediction of failure probability in corroded pipeline in not an easy task, due to the fact that a realistic corrosion usually has an irregular geometry, especially, when multiple irregular corrosion is involved in the analysis. To simplify the problem, this work presents a simplified procedure for time-dependent reliability analysis to predict the failure probability in pipeline with multiple irregular corrosion defects, considering two failure modes, the burst and leak mode. The approach is based on Subset Simulation and Weighted Depth Difference method, where the multiple irregular corrosion is treated by a discretization procedure and a weighting coefficient is evaluated in every discretization points. Then, this weighting coefficient is introduced into burst pressure assessment, which is employed by burst failure mode limit state function. In this work, the corrosion growth is modelled by power function corrosion model, and initial corrosion depth is generated randomly. The Subset Simulation is employed to evaluate the failure probability, where the Markov Chain Monte Carlo is adopted to evaluate the conditional probability and Metropolis-Hasting algorithm is employed to solve the problem. Finally, several scenarios with single and multiple irregular corrosion defects are analyzed to demonstrate the effectiveness of presented procedure.