Rupture Pressure Research Articles

Influence of cyclic loading on physical and mechanical properties of thin-film membrane structures

The principle of modification of mechanical properties of thin-film membrane structures of arbitrary shape by non-contact method was proposed, realized and explained for the first time. The idea was tested on an aluminum thin-film membrane formed by magnetron method on a silicon substrate. The external influence was realized by means of cyclic loading in the form of discharge and supply of excess air pressure to the membrane. As a result of repeated impacts, physical properties of materials (grain size and roughness) and mechanical properties (internal mechanical stresses and critical overpressure) are changed. Changing the magnitude of residual mechanical stresses in the membrane material allows the formation of a surface with a desired curvature value. In this work, after cyclic loading with pressure equal to half of the critical pressure, the following effects were revealed: the deflection of the membrane in the absence of external influence increased by more than an order of magnitude, the structure shifted to the plastic type of deformation, the critical rupture pressure decreased by several tens of percent. Application of this methodology allows to create new materials with unique mechanical properties.

General theory of diaphragm rupture in a shock tunnel

As the flow field starting device is in a shock tunnel, the rupture performance of the diaphragm directly influences the successful formation of the shock wave. The general theory of diaphragm rupture in shock tunnels is proposed first in this paper. The reasons for diaphragm rupture are explained fundamentally. The existing ideologies on diaphragm rupture are unified, and two hypotheses with corresponding methods are introduced. In the ideal diaphragm, diaphragm rupture pressure or rupture time can be predicted by considering the diaphragm opening as a throat through a diaphragm opening aperture. In the non-ideal diaphragm, the control of diaphragm rupture pressure can be realized by considering nominal rupture stress and grooved thickness. The correctness of the general theory of diaphragm rupture is proved through argumentation and based on experimental results of the literature. The general theory of diaphragm rupture can be used to predict the diaphragm rupture behavior of any shock tunnel worldwide and avoid the risk of shearing of petals on the diaphragm caused by the impact load. A new system of diaphragm rupture theory is constituted, and it is of significant importance for the efficient operation of shock tunnel equipment.

Experimental and numerical study of light, fragile vent covers under vented gas explosions

In this study, the venting functions of autoclaved aerated concrete (AAC) and gypsum vent covers under gas explosion conditions were examined for the first time. Eleven sets of field tests were performed, data such as overpressuretime history and rupture pressure data were collected, and failure modes were recorded and analysed. The results show that the AAC and gypsum panels can substantially reduce the internal peak overpressure and duration, and the AAC panel is the venting component with the best performance. The dynamic rupture pressure of venting covers obviously differs from the internal peak overpressure and static failure overpressure, so the opening process and dynamic effect of venting covers should be considered in the design. A numerical model of the AAC panel was established in LS-DYNA. In a parametric study, the panel thickness, material strength, boundary conditions and rate of overpressure rise considerably affected the rupture pressure. On this basis, an empirical formula for the rupture pressure and its applicable range is presented.

Utilization law of shale gas in hydraulic fracturing with the Changning–Weyuan block in China as an example

The process of extracting shale gas, particularly the study of the utilization law of shale reservoirs modified by hydraulic fracturing technology, is crucial for understanding the effective development of shale gas. This understanding can significantly influence the estimated ultimate recovery of reserves. Our study focused on Longmaxi Formation shale in the Changning–Weiyuan block. To investigate the hydraulic fracturing expansion mechanism and utilization law, we employed shale reservoir physical and mechanical characterization, indoor triaxial hydraulic fracturing experiments, and numerical simulations. The findings are as follows. The rupture pressure of hydraulic fractures increases with the peripheral pressure, and high stress is conducive to the formation of internal microfractures. Additionally, a high rate of water injection enhances fracture extensions along the direction of fluid injection. Under varying injection pressures, the length of crack extensions and number of bond damages in shale are positively correlated with the injection pressure. Conversely, under different differential ground stresses, the length of crack extensions and number of bond damages are negatively correlated with the injection pressure. The six main factors affecting the effective utilization of shale gas are as follows: the stimulated reservoir volume, number of hydraulic fracture clusters, fracture length, fracture height, number of fracture stages, and cluster spacing, accounting for 27.13%, 14.74%, 10.31%, 9.58%, 9.53%, and 9.29%, respectively, with a cumulative contribution rate of 80.58%. This study clarifies the hydraulic fracturing mechanisms of shale reservoirs and the laws governing shale gas production, providing technical support for the development of shale gas reservoirs.

Effect of operation condition on the venting characteristics of gas/dust two-phase system explosions

This experiment focused on the study of gas and solid two-phase explosions venting characteristics. A comprehensive research of venting parameter, venting flame propagation, temperature distribution, and the influence mechanism of operation condition were revealed. Results indicate that the venting flame experienced the changes of “mushroom”, “spherical” and “strip” structures and was affected by the initial pressure (Pinit) and the film rupture pressure (Pstat). As Pstat≥0.24 MPa, the flame all exhibited a “mushroom” structure and became more prominent as the film rupture pressure increased. The velocity history was increased in the acceleration venting stage as the film rupture pressure and initial pressures enlarged, and flame exhibited an obvious oscillation during extinguishing stage and the average amplitude was also enlarged. As the film rupture pressure further increased, the secondary and third venting processes appeared. The pressure change at the venting port was more significant, even appeared a larger negative pressure and its drop extent continued to increase as the film rupture pressure and initial pressures raised. Tmax appeared in the center of “spherical” flame approach the front end and the extinguished flame still maintained a higher temperature, resulting in a larger distribution outline than the flame image.

Establishment of a one-dimensional model for CO2 Pipeline rupture process and design recommendations

Pipelines serve as a critical means of transporting CO2 within Carbon Capture, Utilization, and Storage (CCUS) technology. Elevated transport pressures may lead to unforeseen pipeline ruptures. To provide practical recommendations for the design of CO2 pipelines and mitigate the risk of ruptures, this study establishes a one-dimensional Homogeneous Equilibrium Mixture (HEM) model. The model is currently used to predict the decompression behavior in existing pure CO2 rupture tests. Future work will address rupture tests and predictions involving impure CO2. The results indicate that due to differences in pressure reduction caused by decompression waves, the likelihood of long-range ruptures occurring in density CO2 pipelines is lower compared to supercritical CO2 pipelines. The crack propagation velocity and crack arrest pressure of pipelines designed according to ASME B31.3 are calculated using the High Strength Line Pipe Committee (HLP) model. Although the crack propagation velocity is lower than the decompression wave speed, the crack arrest pressure may fall below the rupture pressure, with the pressure at 1.6 m from the rupture point remaining above the crack arrest level for 1 ms post-rupture, a duration that is especially prolonged in larger-diameter pipelines. It is recommended to consider additional thickness beyond the calculated minimum thickness.

Study of rupture behavior of 40Cr ring-scored bursting diaphragms

The rupture diaphragm is a key part of pressure control in the launcher and the reliability of the rupture pressure is directly related to the internal ballistic performance. In order to study the rupture behavior of the 40Cr annular scored diaphragm under internal ballistic conditions and the remaining thickness of the diaphragm’s scoring, the stress-strain curve of the diaphragm is obtained by fitting the internal ballistic loading curve and simulation, the relationship between the rupture pressure and the remaining thickness of the scoring is established and the accuracy of the simulation is verified by the blasting test.

Hemodynamic study of the ICA aneurysm evolution to attain the cerebral aneurysm rupture risk

The influence of the aneurysm evolution on the hemodynamic characteristic of the blood flow inside the sac region is comprehensively investigated. By using the computational method, the blood flow through the vessel and aneurysm of the sac region is examined to find the role of aneurysm evolution on the wall shear stress, pressure, and risk of aneurysm rupture. Three different models of ICA aneurysms are chosen for the investigation of the aneurysm evolution at risk of rupture. Obtained data shows that the evolution of the aneurysm decreases the wall shear stress and pressure on the sac surface while an oscillatory index of blood increases on the aneurysm wall.

Evaluation of two liver biopsy and rectal sealing techniques in dog cadavers undergoing Natural Orifices Transluminal Endoscopic Surgery (NOTES) by transrectal access

The aim of this study was to evaluate two liver biopsy techniques by transrectal Natural Orifice Transluminal Endoscopic Surgery (NOTES) and compare tensiometric parameters of rectal sealing using 2-octyl cyanoacrylate glue or conventional rectal sutures in a dog cadaver model. In sixteen dog cadavers two liver biopsy techniques were performed via transrectal NOTES using either polypectomy diathermy forceps or endoscopic oval biopsy forceps. The cadavers were divided into two groups: Glue Group (GG) where rectal sealing was performed with 2-octyl cyanoacrylate glue and Suture Group (SG) with the rectal defect sealed with simple continuous extracorporeal 3-0 polydioxanone sutures. The rupture pressure of the seals was measured on a rectal burst test. The diathermy polypectomy endoscopic forceps biopsy technique was significantly faster (p<0.001) and provided larger diameter samples. Rectal sealing was significantly faster (p<0.001) in the GG. There was no difference between the two groups with regard to rupture pressure (258.5 mmHg) with air insufflation. Using endoscopic oval biopsy forceps, biopsy samples can only be collected from the surface of the liver, whereas polypectomy forceps with a diathermy loop can be used to collect samples from the tip of the hepatic lobe. There was no difference in rectal rupture pressure in the burst test between the cadavers where sealing was performed with rectal sutures and those where cyanoacrylate adhesive was used.

Investigation of the appropriate viscosity of fibrinogen in repairing pleural defects using ventilation and anchoring in an ex vivo pig model

ObjectiveOur previous study revealed that the viscosity of fibrinogen could influence the effectiveness of ventilation and anchoring (V/A) methods for controlling air leakages. Here, we examined the association between the viscosity of fibrinogen and effectiveness using an ex vivo pig model.MethodsThe fibrin glue used in this study was BOLHEAL® (KM Biologics Co., Ltd., Kumamoto, Japan). We prepared three types of fibrinogen with different viscosities (higher and lower than normal), including one without additives. Using an ex vivo pig model, a pleural defect was made, and the defect was repaired using three different viscosities of fibrinogen through the V/A method. We measured the rupture pressure at the repair site (N = 10) and histologically evaluated the depth of fibrin infiltration into the lung parenchyma at the repair sites.ResultsThe median rupture pressure was 51.5 (40–73) cmH2O in Group 1 (lower viscosity), 47.0 (47–88) cmH2O in Group 2 (no change in viscosity), and 35.5 (25–61) cmH2O in Group 3 (higher viscosity). There was no statistically significant difference between Groups 1 and 2 (p = 0.819), but the rupture pressure was significantly higher in Group 2 than in Group 3 (p = 0.0136). Histological evaluation revealed deep infiltration of fibrin into the lung parenchyma in Groups 1 and 2, but no such infiltration was observed in the higher-viscosity group.ConclusionsThe results of this experiment suggested that the V/A method using fibrin glue containing low-viscosity fibrinogen was more effective in controlling air leakage due to pleural defects.

Overloaded transnidal pressure gradient as the hemodynamic mechanism leading to arteriovenous malformation rupture: a quantitative analysis using intravascular pressure monitoring and color-coded digital subtraction angiography

BackgroundThe hemodynamics of brain arteriovenous malformations (AVMs) may have implications for hemorrhage. This study aimed to explore the hemodynamics of ruptured AVMs by direct microcatheter intravascular pressure monitoring (MIPM) and...

Rupture of membranous microbubbles induced by pulsed acoustic wave

Encapsulated microbubbles serve as suitable drug carriers in medicine. This paper proposes corrections for the resonance frequency of lipid-coated bubbles under various acoustic pressure levels and the critical pressure for bubble rupture based on the Marmottant model. The suggestion to induce the rupture of lipid-coated bubbles using acoustic waves leans toward utilizing pulse waves rather than continuous waves. Corresponding experiments validate the accuracy of these corrections and the rationale behind the suggestion, aligning closely with theoretical predictions. This study offers a more precise predictive framework for the behavior of lipid-coated bubbles under acoustic waves.

Effects of preoperative aortic tortuosity and postoperative hypertension on patient-specific hemodynamics of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a serious dilated vascular disease. The risk factors of aneurysm rupture and postoperative blood pressure are the major clinical concerns. The purpose of this work is to analyze the hemodynamic difference between preoperative and postoperative AAA using patient-specific boundary conditions and explore the rupture risk of AAA with different torsion and to simulate the blood flow of different degrees of hypertension. A three-element Windkessel model is utilized as the outlet boundary condition. 20-sim software and self-developed user-defined functions are used to calibrate the parameters. To analyze the influence of aortic tortuosity on hemodynamics, five AAA geometries with different torsion degrees are modified and obtained. We also grade the hypertension and explore the effect of hypertension after operation. The analysis results are consistent with the patient-specific situation. The results show that stent implantation for aneurysms reduces the pressure at the lesion site and increase the speed and wall shear stress. Vessels with high torsion have lower time-averaged wall shear stress (TAWSS), higher oscillatory shear stress index (OSI) and relative retention time, and more disordered blood flow. After stent implantation, with the increase in blood pressure, TAWSS and OSI continue to increase, and the blood flow speed is also faster. AAA with high torsion is more likely to rupture. In clinical practice, attention should be paid to the degree of torsion of the lesion site. Furthermore, blood pressure should be monitored and controlled in time to prevent postoperative complications.

Results of the use of human platelet-rich fibrin membrane applied on colorrhaphy in nourished and malnourished rats.

To evaluate the effects of platelet-rich fibrin (PRF) on the healing of intestinal sutures in rats. Forty rats were distributed into four groups. Two groups were treated with a standard diet and considered nourished (I and II). Two other groups were treated with cornmeal and considered malnourished (III and IV). All animals underwent cecotomy and cecorrhaphy. Groups II and IV had sutures overlapped with human PRF membrane. The following parameters were evaluated: animal weight, death, rupture site, rupture pressure, collagen, and reticulin dosage in the suture line. The use of PRF did not influence deaths, rupture pressure or rupture location. For malnourished animals, a significant difference was observed in relation to the rupture site, corresponding to the suture line (p = 0.038) and reticulin dosage (p = 0.040), when PRF was used. There was no difference in relation to burst pressures. The use of PRF did not influence intestinal healing in nourished rats. In the group of malnourished animals, its use favored healing.

Research on the Design Method of Blueberry Automatic Harvesting Clamp Force Based on Neural Networks

Highlights The relationship between fruit size and gripping force was found by BP algorithm. The error between the optimized holding force and the optimal value is not more than 8%, that is, the fruit integrity rate is greater than 92%. The simplified two-parameter method is more suitable for efficient field operation. Abstract. The flourishing development of the blueberry industry has urgently demanded mechanized harvesting, and the rational design of the clamping force of mechanical claws is a challenging aspect for achieving automatic and flexible harvesting. This article proposes a method to predict fruit hardness based on blueberry shape parameters, enabling dynamic adjustment of clamping force. Fruit diameter, height, weight, and rupture pressure data were collected, and using the classical BP neural network algorithm, a mapping relationship between fruit hardness and shape parameters was established. Experimental verification was conducted using an orthogonal table, and the results indicate that the predicted blueberry fruit hardness using this method deviates by less than 8% from the actual values. Further simplification into a two-parameter method was performed to enhance practical field operation efficiency. Although the error slightly increased, it still met the requirements of actual field operations.

Phase behavior of colloidal nanoparticles and their enhancement effect on the rheological properties of polymer solutions and gels.

The interaction between nanoparticles and polymers has been of great interest in colloidal theory and novel materials. For example, the properties of polyacrylamide solutions and gels, which are usually used for conformance control and water shut-off in oilfields, can be improved with the addition of nanoparticles. This underlying mechanism and its applicability are investigated in this paper. A strong relationship between the phase behaviors of nanoparticles in polymer solutions and their enhancement effect on the rheology of the nanocomposite polymer solutions and gels was observed. Experiment results showed that the stability of nanoparticles was dependent on several factors, including pH, salinity, and polymer type. At neutral pH conditions, the tendency of the aggregation of nanoparticles was strengthened upon increasing the salinity, polymer concentration, and electronegativity of the polymers. Rheological measurements showed that nanoparticles could improve the viscosity of polymer solutions or the fracture stress of gels only if nanoparticles were aggregated in the corresponding systems. In addition, these rheological parameters significantly increased with increasing salinity and nanoparticle concentration. As a result, the mobility ratio of polymer solutions may be increased several times by the addition of nanoparticles. Referring to the gels, their rupture pressure gradient in the ideal model was also found to increase with nanoparticle concentration. In particular, if the nanoparticle concentration was sufficiently high (reaching 2%), the formed gels would not be destroyed by the injected water, but rather functionally act as a porous medium for permeation.

Exploring the Mechanism of Pulse Hydraulic Fracturing in Tight Reservoirs

Pulse hydraulic fracturing is capable of creating intricate seam networks for improved reservoir recovery, but its dynamic damage mechanism remains unclear, limiting its scientific guidance for fracturing construction. This study combined the statistical damage and viscoelastic models according to the D-P criterion and fluid flow continuity equation to establish a mathematical model of the fluid–solid coupling under pulsed hydraulic pressure. The finite element approach was used to investigate the dynamic response and damage accumulation law of tight reservoirs under various pulse parameters. The model’s correctness was verified with indoor triaxial pulse hydraulic fracturing studies, and the Changqing oilfield’s pulse hydraulic fracturing parameters were optimized. The results showed that the rock body around the borehole sustained dynamic damage when exposed to pulsed fluid pressure. The impact force increases with frequency; however, when the frequency is too high, the dynamic pore pressure cannot be stabilized. Consequently, the damage to the rock mass starts to increase and then progressively decreases with higher pulse frequencies. The ideal frequency was found to be 1 Hz. The rock body steadily accumulates damage as the number of pulses rises, increasing the damage value gradually. At the same frequency, the damage is higher for larger pulse amplitudes and ground stress differences, as well as a smaller modulus of elasticity. Pulse cycling reduces the rupture pressure by up to 26% compared to conventional hydraulic fracturing. Moreover, the Sine wave is 4–20% better than the triangle wave. The pulse damage mechanism and parameter optimization in this paper provide theoretical support for improving the effect of hydraulic fracture modification.

Consequences analysis of the LPG tank truck traffic accident: A case study of the Wenling explosion accident

Liquefied Petroleum Gas (LPG) is a vital energy source as well as a chemical feedstock, known for its flammable and explosive property. The demand for LPG has increased in recent years, leading to the frequent occurrence of leaks and explosion accidents, which pose a serious threat to public safety. This paper investigates the process of the consequences evolution of leakage of LPG and explosion accidents, using the Wenling, Zhejiang, China, LPG tanker explosion accident as an example. The main explosive processes that occurred after the leak, i.e., Boiling Liquid Expanding Vapor Explosion (BLEVE) and Vapor Cloud Explosion (VCE), were reconstructed through the collection and organization of data from the incident. The EFFECTS software was used for the simulation of container rupture, vapor dispersion and explosion pressure. The simulation results were consistent with the actual on-site effects. Multi-energy TNO method was used to measure the impact of VCE on overpressure hazards. This resulted in a blast energy of 3.1 × 105 MJ and a staff wound radius of 324 m. Based on the site's terrain and traffic route layout, measures were proposed to install protective walls around the turnaround area. Effective measures were taken to reduce the range and intensity of the explosion and thus to mitigate the consequences of the accident. This measure reduced the damage radius of the accident by 25.6%. This work will serve as a reference for investigation, analysis, scenario development and recommendations to prevent accidents.

Digital manufacturing in laser powder bed fusion of aluminium alloy safety feature for EV battery cell

Recently, a new way to produce prismatic Li-ion battery cell’s lid part for Battery Electric Vehicles (BEV) was presented, with integrated cell thermal management, based on the Laser Additive Manufacturing (LAM) method. In the solution, the safety vent protects the battery cell from unpredictable explosions caused by the increasing internal pressure. Additive manufacturing allows integrating the feature to the cell lid part and significantly decreases the process steps in manufacturing and increases the production efficiency. Aluminium powder materials for the used Laser Powder Bed Fusion (LPBF) method have relatively high tensile strength, which causes the need for minimum layer thickness for the safety vent. Reliability of producing such a thin layer as a gas tight structure is challenging and several procedures were studied. Material with lower tensile strength and higher elongation ability was tested during the second phase. The challenge is to produce such a thin wall thickness, which breaks at the pressure level of one MPa and opens the valve. The design is based on FEM analysis with constant equivalent strain theory to optimize safety vent dimensions. The pressure test was performed to measure the rupturing pressure of the thin aluminium LPBF layer as materials in normal mode and in annealed mode. The constant equivalent strain theory for estimate rupture pressure was in fine agreement with the experimentally measured ones, even with a maximum error rate. The results show that the manufacturing method is possible for such automotive mass production parts and when comparing different stacking strategies, it showed a great influence in the productivity of such parts’ production.

Investigation of the smashing characteristics induced by energy distribution of CO2 BLEVE for coalbed methane recovery

Failure in the near field of coal by liquid CO2 phase transition blasting (LCO2-PB) is the major reason for fracturing performance and enhancing coalbed methane (ECBM) recovery. Features to clarify this failure are of significant importance for the field projects. Some studies have revealed that the energy of LCO2 releasing can determine the damage feature to some extent. This study was therefore initiated to investigate the effect of BLEVE energy on the fracturing performance of LCO2-PB in coal. A series of LCO2-PB fracturing tests was carried out on hard and soft coal to examine the effect of CO2 BLEVE energy on fracture morphology. It was obtained that, compared with fractal dimension of hard coal under lower import energy (623.48 kJ) is around 2.17, the higher import energy (831.36 kJ) provides a larger fractal dimension (2.32), especially for high rupture pressure (95 MPa), which make fragments smash into a smaller radial. Although higher input energy favours a large superfluous energy density for any coal types, soft coal represents a stronger tendency to fracture in the stress drop stage. Lower input energy in hard coal seam products a longer main fracture, and excellent fracturing in soft coal prefers the higher import energy.