Airbag Pressure Research Articles

Validation of a generic finite element vehicle buck model for near-side crashes

Objective Finite element (FE) reconstructions of motor vehicle crashes using human body models are effective tools for developing a better understanding of occupant kinematics and injuries in real-world lateral crash conditions, but current near-side reconstruction methods are limited by the paucity of full-scale FE vehicle models. The objective of this study was to validate a generic vehicle model equipped with left-side airbags and intrusion capability by simulating a series of near-side crash tests for a range of vehicles and assessing model accuracy using objective evaluation methods. Methods Moving deformable barrier crash tests were reconstructed for five common vehicle classifications (compact passenger, mid-size passenger, sport utility vehicle, pickup truck, and van) using an updated version of a previously developed simplified vehicle model. Unknown vehicle and intrusion properties (pretensioner force, seatback airbag pressure, curtain airbag pressure, door panel stiffness, ratio of dynamic-to-static intrusion, intrusion velocity, and intrusion scaling factor) were estimated by parameterizing them across 224 simulations per crash test using a Latin hypercube design of experiments. Model accuracy was assessed for 13 anthropomorphic test device signals using the Correlation and Analysis (CORA) objective rating method and injury metric comparisons. Results Maximum ratings of 0.69, 0.67, 0.52, 0.52, and 0.62 were achieved for the compact passenger, midsize passenger, sport utility vehicle, pickup truck, and van classifications, respectively. On average, the abdomen displayed the most accurate behavior (0.51 ± 0.12), followed by the thorax (0.50 ± 0.10) and head (0.50 ± 0.07). The pelvis displayed the least accurate behavior (0.46 ± 0.18) of any region. Reconstructions overpraedicted injury metrics in all cases. Conclusions All vehicles achieved “fair” biofidelity ratings and the compact passenger and midsize passenger vehicles achieved “good” biofidelity ratings, validating them for kinematic evaluations with vehicle-to-vehicle nearside crash reconstructions. Regression models were developed for injuries and CORA ratings and can be used to optimize vehicle parameters in future studies.

Analytical modeling and experiments on soft soil consolidation with vacuum preloading‐airbag pressurization

AbstractThis study aims to provide substantial theoretical support for employing vacuum preloading‐airbag pressurization (VP‐AP) to enhance soft soil foundations. By integrating the airbags and prefabricated vertical drains (PVDs) within the analytical framework, the consolidation models are developed to accommodate double smear zones and well resistance. Analytical solutions for various airbag pressurization scenarios are derived under the equal‐strain assumption. A model test is subsequently conducted to investigate the settlement process of soft soil using the VP‐AP method. The validity of the proposed theoretical model is corroborated through comparison with existing analytical solutions and experimental data. The accuracy of the predictive model is further substantiated by the model test results. Lastly, this research offers an in‐depth analysis of soil consolidation behavior under diverse influencing factors. The findings indicate that the VP‐AP method demonstrates superior efficacy over conventional vacuum‐surcharge preloading when the airbag pressure matches the external load pressure. Additionally, an increase in the radius of airbags enhances the soil consolidation efficiency. The analytical model presented in this study elucidates the consolidation mechanisms of the VP‐AP method, with experimental research confirming the efficacy of this approach and the predictive model established herein.

Frost protection mechanism based on rubber airbag interlayered composite lining system for cold-region tunnels

To solve the problem of freezing damage in cold-region tunnels, this study proposed a rubber airbag interlayered composite lining system, and tested its performance of buffering, pressure adjustment, waterproofing, and heat preservation by simulating a low-temperature environment in an artificial freezing chamber. The experiment results show that the frost-heaving force exerted on the lining can always be lower than 1.69 kPa by constantly adjusting the airbag pressure, and the maximum frost-heaving force can reach 28.25 kPa without the airbag. In addition, the airbag also has good waterproof performance. Finally, the airbag can significantly improve the temperature field of the surrounding rock and reduce the freezing depth (6.75 cm < 17.25 cm). The insulation effect of the airbag is positively correlated with its thickness and negatively correlated with the thermal conductivity of the filling gas. The insulation effect of CO2 is better than that of air. The rubber airbag interlayered composite lining system provides a new scheme for freezing damage control in cold-region tunnels.

3D simulations and laboratory experiments to evaluate a dynamic airbag valve

Airbag pressure determines the restraint effect during a vehicle crash. The pressure required to restrain the occupant depends on pre-crash detection, collision parameters and the occupant’s mass and position. This work modulated airbag pressure for optimum safety using a novel airbag control valve for cold-gas inflators. This paper evaluates the valve’s stationary and dynamic performances for Helium by 3D flow simulations using a pressure-based solver in ANSYS Fluent® and SAE J2238 laboratory tank tests. The predicted and measured tank pressures for the fully open (stationary) valve were agreed by an average 93.73% with an excellent correlation (correlation coefficient, R = 0.9995). For the first dynamic operation with 10 ms switching time, the results agreed by 92.78% with R = 0.9975. In the second test with 30 ms switching, 83.67% agreement was observed with R = 0.9893. The research concluded that the valve modulates the bag pressure and is implementable in vehicles.

Application of health failure mode and effect analysis for the airbag pressure management of patients with artificial airways

To analyze the application effect of health failure mode and effect analysis (HFMEA) model in patients with artificial airways in the cardiovascular surgery intensive care unit (CSICU) by establishing a HFMEA project team, and to develop targeted improvement measures and processes. The patients undergoing cardiovascular surgeries and with established artificial airways in the Shandong Provincial Hospital Affiliated to Shandong First Medical University were recruited from October 2021 to March 2022. The enrolled patients were divided into the conventional management group and the HFMEA model management group according to random number table method. The conventional management group applied the conventional procedures for monitoring the air bag pressure. The HFMEA model management group used the HFMEA model to implement and improve the airbag pressure monitoring process. The efficacy of HFMEA was assessed by comparing the incidence of ventilator-associated pneumonia (VAP), the pass rate of airbag pressure monitoring, the duration of endotracheal intubation and the length of CSICU stay between two groups. The practicability of HFMEA model was evaluated by analyzing the theoretical assessment scores and practical skill scores of nurses and their satisfaction scores with HFMEA. Compared with the conventional management group, the patients in the HFMEA mode management group had a significantly higher rate of passing airbag pressure monitoring [94.99% (2 994/3 152) vs. 69.97% (1 626/2 324), P < 0.01], shorter duration of endotracheal intubation and length of CSICU stay [duration of endotracheal intubation (hours): 6 (7, 12) vs. 6 (8, 13), length of CSICU stay (hours): 40 (45, 65) vs. 41 (46, 85), both P < 0.05], but the incidences of VAP between the two groups were similar. The theoretical assessment scores and practical skill scores of nurses were significantly higher (theoretical assessment score: 44.47±2.72 vs. 37.59±6.56, practical skill score: 44.56±2.66 vs. 40.03±4.32, total score: 89.03±3.07 vs. 77.63±9.56, all P < 0.05) in the HFMEA mode management group. And the satisfaction scores with airbag pressure management were also significantly higher in the HFMEA mode management group (7.72±1.11 vs. 6.44±1.32, P < 0.05). The application of the HFMEA can improve the airbag pressure measures and standardize the monitoring procedures in patients with artificial airways, and reduce the risk of clinical nursing. It is safe and effective for patients with invasive mechanical ventilation in the CSICU.

Design and Application of Intelligent Management System of Artificial Airway Airbag Pressure in Intensive Care

In order to solve the problem of continuous monitoring and automatic regulation of patient airbag pressure in intensive care unit, the study designed an intelligent management system of artificial airway airbag pressure. It can realize real-time monitoring and automatic control of airbag pressure. Its pressure data was sent to the PC in real time by the serial port. It can realize the display, store, review and analysis of pressure data. Its clinical application effect was discussed. Experiments showed that the system can monitor airbag pressure in real time and control the pressure to stabilize at 25~30 cmH2O. Compared with the control group, the experimental group had a statistically significant difference in the operation time of monitoring patients' airbag pressure, changes in airbag pressure, the instantaneous maximum value during nursing operation, and the number of aspiration and reflux cases. The clinical application of the system can reduce the workload of medical staff greatly, effectively reduce the number of patients with aspiration and reflux, reduce the incidence of ventilator pneumonia.

Development and Design of Flexible Sensors Used in Pressure-Monitoring Sports Pants for Human Knee Joints

Flexible pressure sensors are being used widely in sports and human-health monitoring. The knee joint is one of the organs with the highest injury rate while running. By optimizing the structural design of sports pants, the lower limbs can be compressed appropriately to protect the knee joint and improve exercise efficiency. The point of innovation lies in the removable flexible pressure sensors implanted in these leggings developed to monitor the three-dimensional force on the knee in real time. Combined with data analysis, this can provide information to wearers while exercising and to the middle-aged and elderly to prevent knee-strain problems. The experimental results showed that the pressure values of the left and right knee joints measured using the flexible pressure sensors on the leggings in real time and those obtained using the AMI3037-5s Airbag pressure tester were accompanied by F-values and t-test statistical probability values greater than 0.05. This indicates that there was no significant difference between the two values, reflecting the credibility of the flexible pressure-monitoring data. The oxygen saturation and total hemoglobin content of a subjects’ legs after exercising were higher than those before exercising, indicating that the leggings performed well in terms of fatigue relief. The subjects’ body surface temperature, when exercising, changed steadily and dropped gradually in the later stage, indicating that the leggings perform well with respect to thermal and moisture comfort. Flexible sensing technology has promising application prospects in wearable smart clothing in future, particularly in the sports and health fields.

Blunt injury of liver: mechanical response of porcine liver in experimental impact test

Objective. The liver is frequently injured in blunt abdominal trauma caused by road traffic accidents. The testing of safety performance of vehicles, e.g. belt usage, head support, seat shape, or air bag shape, material, pressure and reaction, could lead to reduction of the injury seriousness. Current trends in safety testing include development of accurate computational human body models (HBMs) based on the anatomical, morphological, and mechanical behavior of tissues under high strain. Approach. The aim of this study was to describe the internal pressure changes within porcine liver, the severity of liver injury and the relation between the porcine liver microstructure and rupture propagation in an experimental impact test. Porcine liver specimens (n = 24) were uniformly compressed using a drop tower technique and four impact heights (200, 300, 400 and 500 mm; corresponding velocities: 1.72, 2.17, 2.54 and 2.88 m s−1). The changes in intravascular pressure were measured via catheters placed in portal vein and caudate vena cava. The induced injuries were analyzed on the macroscopic level according to AAST grade and AIS severity. Rupture propagation with respect to liver microstructure was analyzed using stereological methods. Main results. Macroscopic ruptures affected mostly the interface between connective tissue surrounding big vessels and liver parenchyma. Histological analysis revealed that the ruptures avoided reticular fibers and interlobular septa made of connective tissue on the microscopic level. Significance. The present findings can be used for evaluation of HBMs of liver behavior in impact situations.

Assessment of Several THOR Thoracic Injury Criteria based on a New Post Mortem Human Subject Test Series and Recommendations.

Several studies, available in the literature, were conducted to establish the most relevant criterion for predicting the thoracic injury risk on the THOR dummy. The criteria, such as the maximum deflection or a combination of parameters including the difference between the chest right and left deflections, were all developed based on given samples of Post Mortem Human Subject (PMHS). However, they were not validated against independent data and they are not always consistent with the observations from field data analysis. For this reason, 8 additional PMHS and matching THOR tests were carried out to assess the ability of the criteria to predict risks. Accident investigations showed that a reduction of the belt loads reduces the risk of rib fractures. Two configurations with different levels of force limitation were therefore chosen. A configuration representing an average European vehicle was chosen as a reference. It consists of a 3-point belt with a 3.5 kN and then 2 kN digressive limiter, combined with a 54-liter airbag. For better reproducibility and durability, the tests were performed with a pre-inflated bag and a semi-rigid seat. In this first configuration, the THOR dummy had a maximum resulting deflection of 43 mm. To differentiate the criteria, the second configuration was chosen such that it resulted in about the same deflection on the THOR dummy, but with a 5 kN belt force limitation combined with a lower pressure airbag. To reach this target of 43 mm, the pulse severity was lowered. Some criteria were higher in this second configuration, which allows them to be distinguished from the maximum deflection criterion. Four tests on four PMHS were performed in each configuration. The injury assessments showed that the total number of fractures was almost the same in both configurations, but that the number of separated fractures was greater in the 5 kN configuration. 25% of the subjects sustained AIS >3 injuries related to the number of displaced fractures in the 3.5/2 kN load limitation configuration. The result increased to 75% in the 5kN configuration. In total, 8 PMHS and the matching THOR tests were performed and used to assess the ability of the thoracic criteria to predict rib fractures in 2 types of chest loading configurations. The test results did not allow to conclude on the relevance of the criteria measured on the THOR dummy for the total number of rib fractures identified at autopsy (NFR). However, clearly different assessments for separated rib fractures (NSFR), make it possible to differentiate the criteria. The maximum resultant deflection failed to properly predict separated rib fractures while other criteria that include the left-to-right rib deflection difference did.

Status quo and countermeasure analysis of ICU nurses' implementation of airbag pressure monitoring in artificial airway

Objective To investigate the execution rate of airbag pressure monitoring of artificial airway by ICU nurses, and analyze the countermeasures to improve the execution rate of airbag pressure monitoring. Methods From May to June 2017, 15 patients who were admitted to the ICU of this hospital with retained artificial airway and mechanical ventilation time greater than 24 hours were randomly selected.The 418 times of airbag pressure monitoring in 15 patients during mechanical ventilation were recorded, and the implementation of airbag pressure monitoring in nurses at different time points and with different seniority was compared, and the influence of nurses' teaching on airbag pressure monitoring was analyzed. Results Total execution rate of airbag pressure monitoring was 45.93%.The comparison of airbag pressure monitoring implementation rates at different time points within 24 hours showed statistically significant differences (P<0.05). The execution rate in the afternoon was higher than that in the morning, and pre-night shift was higher than that of post-night shift, the difference was statistically significant (P<0.05). The execution rate of nurses within 3 years was higher than that of nurses over 3 years, and the difference was statistically significant(P<0.05). The execution rate of nurses with teaching was higher than that of nurses without teaching, the difference was statistically significant(P<0.05). Conclusions The execution performance of airbag pressure monitoring among ICU nurses is not optimistic.It is necessary to improve their execution performance from training, changing the work flow of nursing, setting an example or improving the nurses' subjective initiative, improving monitoring method, etc. Key words: ICU nurses; Artificial airway; Airbag pressure monitoring; Execution rate

Airbag application to passenger seat for aircraft: impact tests

Impact tests were conducted for an airbag that was installed as an aircraft seat cushion to reduce the shock to passengers in the case of an emergency. A falling body was dropped against a pre-inflated test airbag which was equipped with an exhaust orifice. Acceleration and displacement of the falling body and the inner pressure of the test airbag were measured. The influences of diameter, length and rupture pressure of the exhaust orifice on the shock absorbability of the airbag were investigated.

Chest injuries of elderly postmortem human surrogates (PMHSs) under seat belt and airbag loading in frontal sled impacts: Comparison to matching THOR tests

Objective: The goal of the study was to develop experimental chest loading conditions that would cause up to Abbreviated Injury Scale (AIS) 2 chest injuries in elderly occupants in moderate-speed frontal crashes. The new set of experimental data was also intended to be used in the benchmark of existing thoracic injury criteria in lower-speed collision conditions.Methods: Six male elderly (age >63) postmortem human subjects (PMHS) were exposed to a 35 km/h (nominal) frontal sled impact. The test fixture consisted of a rigid seat, rigid footrest, and cable seat back. Two restraint conditions (A and B) were compared. Occupants were restrained by a force-limited (2.5 kN [A] and 2 kN [B]) seat belt and a preinflated (16 kPa [A] and 11 kPa [B]; airbag). Condition B also incorporated increased seat friction. Matching sled tests were carried out with the THOR-M dummy. Infra-red telescoping rod for the assessment of chest compression (IRTRACC) readings were used to compute chest injury risk. PMHSs were exposed to a posttest injury assessment. Tests were carried out in 2 stages, using the outcome of the first one combined with a parametric study using the THUMS model to adjust the test conditions in the second. All procedures were approved by the relevant ethics board.Results: Restraint condition A resulted in an unexpected high number of rib fractures (fx; 10, 14, 15 fx). Under condition B, the adjustment of the relative airbag/occupant position combined with a lower airbag pressure and lower seat belt load limit resulted in a reduced pelvic excursion (85 vs. 110 mm), increased torso pitch and a substantially lower number of rib fractures (1, 0, 4 fx) as intended.Conclusions: The predicted risk of rib fractures provided by the THOR dummy using the Cmax and PC Score injury criteria were lower than the actual injuries observed in the PMHS tests (especially in restraint condition A). However, the THOR dummy was capable of discriminating between the 2 restraint scenarios. Similar results were obtained in the parametric study with the THUMS model.

Biomechanical simulation of eye-airbag impacts during vehicle accidents.

Airbags are safety devices in vehicles effectively suppressing passengers' injuries during accidents. Although there are still many cases of eye injuries reported due to eye-airbag impacts in recent years. Biomechanical approaches are now feasible and can considerably help experts to investigate the issue without ethical concerns. The eye-airbag impact-induced stresses/strains in various components of the eye were found to investigate the risk of injury in different conditions (impact velocity and airbag pressure). Three-dimensional geometry of the eyeball, fat and bony socket as well as the airbag were developed and meshed to develop a finite element model. Nonlinear material properties of the vitreous body and sclera were found through the in vitro tests on ovine samples and for the other components were taken from the literature. The eye collided the airbag due to the velocity field in the dynamic explicit step in Abaqus. Results of compression tests showed a nonlinear curve for vitreous body with average ultimate stress of 22 (18-25) kPa. Tensile behavior of sclera was viscoelastic nonlinear with ultimate stresses changing from 2.51 (2.3-2.7) to 4.3 (4-4.6) MPa when loading strain rate increased from 10 to 600 mm/min. Sclera, ciliary body, cornea and lens were the eye components with highest stresses (maximum stress reached up to 9.3 MPa). Cornea, retina and choroid experienced the highest strains with the maximum up to 14.1%. According to the previously reported injury criteria for cornea, it was at high risk of injury considering both stress and strains. Reduced pressure of the airbag was beneficial decreased stress of all components. Comprehensive investigations in this area can disclose biomechanical behavior of the eye during eye-airbag impact. Effective guidelines can be drawn for airbag design for instance the airbag pressure which reduces risk of eye injury.

Shell Structure Water Cellar’s Rapid Construct Technology

Tradition concrete water cellar’s problems, such as high cost, long construction term, easy to crack, are pointed out. A new construct method, and it’s matching airbag mould, of constructing concrete shell structure water cellars, are introduced. Combine with full-scale verifying cellar’s construct test, full-load water storage test, analyzed the technology in terms of construction term, cost, crack resistance, air bag pressure etc. It is believed that this new technology can successfully solve the problems that tradition technology has, and it will have a good prospect in rainfall resources utilization.

Minimal amount of air bag pressure and external cryocoagulation of retina for the treatment of retinal detachment

Objective To observe the efficacy of minimal amount of air bag pressure and external cryocoagulation of retina for the treatment of retinal detachment. Methods The data of 34 eyes of 34 cases with rhegmatogenous detachment of retina were collected and analyzed retrospectively .They underwent minimal amount of air bag pressure combined with external cryocoagulation of retina.The retinal reattachment, corrected visual acuity and complications were observed after surgery.The follow-up period was 5-12 months. Results In 34 eyes, retinal reattachment was found in 31 eyes( 91.18%), poor retinal reattachment in 3 eyes, included irregular crack hole of 1 eye and pseudophakic of 2 eyes.Among 3 eyes, 2 eyes underwent scleral buckling operation and 1 eye underwent vitrectomy combined with C3F8 tamponade.The omissive retinal tear caused the first surgrey faliure was found during the second surgery. Among 31 eyes of retinal reattachment, retinal detachment recurred in 3 eyes 1 month after surgery, 2 eyes were horse-shoe holes located in the upper quadrant, 1 eye was pseudophakic.Among them, 1 eye underwent scleral buckling operation, 2 eyes underwent vitrectomy combined with silicone oil tamponade after retinal reattachment. At the last follow-up, retinal reattachment were in 32 eyes, corrected visual acuity improved 5-10 lines in 23 eyes (67.65%), improved 3- 4 lines in 8 eyes (23.53%), and 3 eyes without significant changes (8.82%). No serious complication occurred. Conclusion Minimal amount of air bag pressure and external cryocozgulation of retina for the treatment of rhegmatogenous retina detachment is safe and effective, with short time of operation, small incision and less pain to the patients, rapid recovery after operation and keeping more field for other operations. Key words: Retinal detachment, rhegmatogenous; External cryocozgulation of sclera; Air bag pressure

Risk factors of aspiration of gastrointestinal contents in patients with mechanical ventilation in neurosurgical ICU

Objective To explore the high-risk factors of tracheobronchial aspiration of gastric contents of patients in Neurosurgical ICU, so as to provide basis for aspiration prevention as well as related complications. Methods The prospective cohort study was conducted during the patients with mechanical ventilation who were continuously enrolled. The general information and condition of 74 patients from two tertiary hospitals were recorded and their tracheal secretions were collected. The content of pepsin A in airway secretions was determined whether there is an aspiration. Results The incidence rate of aspiration in 74 patients was 39.2%. The chi-square test results showed that the angle of backrest elevation, the rate of enteral nutrition pump, diameter of nasogastric feeding tube, gastric residual volume, airbag pressure, Glasgow score and the use of sedatives were all related to the occurrence of aspiration (χ2/F =30.771, 16.845, 11.471, 9.212, 6.582, 15.664, 11.722, 18.312; P<0.05) . Logistic regression analysis indicated five risk factors related to aspiration, including bed elevation angle, rate of enteral nutrition pump speed, airbag pressure, whether the use of sedatives and gastric residual volume. AUC of risk score calculation is 0.994, RR=1.979 (1.351, 2.900) . The risk of patients whose AUC score≥10 was double of patients whose AUC score<10. Conclusions To reduce the incidence of aspiration of gastric contents, for patients without contraindications, angle of backrest greater than 30 degrees, maintaining cuff pressure between 20 and 30 cmH2O, nasogastric feeding rate<25 ml/hour, small bowel feeding rate<45 ml/hour, and GRVs ≥50 ml, gastric feedings and enteral nutrition are recommended; pay attention to patients usingsedative drugs, can also reduce the aspiration rate of gastric contents. Key words: Gastrointestinal contents; Risk factors; Neurosurgery; Intensive care unit; Aspiration

Effect of evidence-based nursing training on delicacy management of artificial airway

Objective To investigate the influence of evidence-based nursing training scheme on knowledge and nursing behavior of nursing staff concerning artificial airway management, and to observe clinical effect of the training. Methods 76 nurses in ICU in Department of Neurology were trained with evidence-based nursing of delicacy management of artificial airway. Their knowledge about artificial airway and normalization of nursing behavior were compared before and after the training. Meanwhile, occurrence rates of hospital acquired pneumonia (HAP) and ventilator associated pneumonia (VAP) of 88 patients with artificial airway before and after the training were compared. Results Before the training, scores of nurses′ theoretical knowledge on normalized management of artificial airway were (69.05±5.09), while the scores were (89.05±4.13) after the training (t=-26.587, P<0.01). After the training, passing percentage of nursing operations of oral care after orotracheal intubation, airway suction, airbag pressure monitoring and dressing change after tracheotomy were 90.8%, 93.4%, 94.7% and 92.1%, all higher than the percentage before the training (χ2=16.369, 11.878, 10.417, 11.207; P<0.01). After the training, occurrence rate of HAP and VAP in patients with artificial airway was both 16.7%, lower than before the training (χ2=4.905, 4.795; P<0.05). Conclusions Evidence-based nursing training on standardized management of artificial airway can improve the nurses′ theoretical knowledge, standardize nursing behavior, decrease occurrence rate of HAP/VAP of patients with artificial airway, and provide scientific management strategies for nursing managers on delicacy management of artificial airway. Key words: Artificial airway; Evidence-based nursing; Delicacy management; Training

A novel multi-functional water façade system for energy saving and blast resisting

A novel multi-functional water façade system with the combined function of energy saving and blast resisting is presented in this paper. The façade system utilizes water confined in a thin tank to harness the solar thermal energy and to shield the building from solar radiation. It is particularly suitable for hot climate regions near the Equator due to the constant high dense solar radiation throughout the year. The energy saving performance of the water façade in terms of harnessing the solar thermal energy and reducing space cooling load was evaluated by conducting temperature monitoring tests. As for its potential as a protective layer against blast loading, the water façade was tested under simulated blast loading through dropping projectile on an inflated high pressure airbag. The addition of water was shown to reduce the displacement of water façade and improve the blast resistant capacity through comparing the maximum displacements of the water façades with and without infilled water. An analytical model incorporating varying dynamic increase factor and coupled deflection mode shapes was developed to predict the displacement response of water façade under blast loading and the analytical predictions on maximum displacement were conservative as compared to those from finite element analyses.

Structural performance of water tank under static and dynamic pressure loading

The structural performance of water tank under static and dynamic pressure loading was experimentally investigated in this paper. The loading was applied using hydraulic actuator/dropped projectile on an inflated high pressure airbag to assert static/dynamic pressure on the specimens. The failure modes and maximum resistance of the specimens were obtained from the test and compared to the numerical results. It was found from the static pressure test that the water tank filled with water exhibited up to 31% increase in flexural resistance under static loading as compared to the empty water tank with the same material and geometry. The improvement was attributed to the effects of water in maintaining the section modulus and delaying the local buckling of the tank. Water was also found to be useful in reducing the deformation of the tank under dynamic pressure loading. Nonlinear finite element analysis was conducted to investigate the behavior of water tank subject to static and dynamic pressure loading and the accuracy of the numerical models was verified by comparing the predicted displacement responses with those observed from the tests.

Experimental and numerical studies of non-composite Steel–Concrete–Steel sandwich panels under impulsive loading

Abstract The performance of non-composite Steel–Concrete–Steel (SCS) sandwich panels under impact-induced impulsive loading was experimentally and numerically studied in this paper. Two SCS sandwich panels with different core depths were tested and the impulsive loading was applied in the laboratory by utilizing an inflated high pressure airbag to transfer the impact load from dropped projectile onto the panels. The deformation modes, applied pressures, displacement and strain responses of the panels were determined in the test. A combination of bending and shear deformation mode was observed in the SCS panel with thinner core while there was minimal visible deformation in the thicker panel. The maximum and permanent deformations of the panel with thicker panel were significantly reduced due to the increase in resistance and mass. Debonding between grout core and bottom plate was also noted in both panels during impact from the strain–time histories. Following the test, Finite Element (FE) models were constructed and verified against the test data to simulate the tests. It was shown in the FE analysis that the steel plates absorbed more energy due to its higher strength and ductility as compared to the grout core under the impact-induced impulsive pressure loading.