Numerical Study of Corrugated Metal Panels Subjected to Windborne Debris Impacts

2014 ◽  
Vol 626 ◽  
pp. 109-114
Author(s):  
Wen Su Chen ◽  
Hong Hao ◽  
Hao Du
Keyword(s):  
Extreme Event ◽  
Numerical Study ◽  
Numerical Models ◽  
Economic Loss ◽  
Wind Loading ◽  
Windborne Debris ◽  
Study Laboratory ◽  
The Impact ◽  
Metal Panels ◽  
Corrugated Metal

Hurricane, typhoon and cyclone take place more and more often around the world with changing climate. Such nature disasters cause tremendous economic loss and casualty. Various kinds of windborne debris such as compact-like, plate-like and rod-like objects driven by hurricane usually imposes localized impact loading on the structure envelopes such as cladding, wall or roof, etc. The dominant opening in the envelope might cause serious damage to the structures, even collapse. To withstand the impact of such extreme event, the requirements on panel capacity to resist windborne debris impact has been presented in the Australian Wind Loading Code (2011) [1]. Corrugated metal panels are widely used as building envelop. In a previous study, laboratory tests have been carried out to investigate the performance of corrugated metal panels subjected to a 4kg wooden projectile by considering various impact locations, impact velocities and boundary conditions. In this study, numerical models were developed to simulate the responses of the corrugated metal panels subjected to wooden debris impacts by using commercial software LS-DYNA. The predicted data from the numerical simulations were compared with the experimental results. The validated numerical model can be used to conduct intensive numerical simulation to study the failure probabilities of corrugated structural panels subjected to windborne debris impacts.

Numerical Study of Basalt Fibre Cloth Strengthened Structural Insulated Panel under Windborne Debris Impact

2016 ◽  
Vol 846 ◽  
pp. 446-451 ◽  
Author(s):  
Qing Fei Meng ◽  
Hong Hao ◽  
Wen Su Chen
Keyword(s):  
Numerical Model ◽  
Structural Damage ◽  
Numerical Study ◽  
Building Envelope ◽  
Basalt Fibre ◽  
Structural Wall ◽  
Windborne Debris ◽  
Strong Winds ◽  
The Impact ◽  
Debris Impact

Strong winds happen around the world every year and cause enormous damages and losses. Besides large wind pressure, impact from windborne debris on building envelope is a major source of structural damage in strong winds. The debris lifted and carried by wind impacting on building envelop may create openings on building envelope which increase internal pressure of the building, and lead to roof lifting and even total building collapse. Preventing impact damage to structural wall and roof is therefore critical in extreme wind conditions. On the other hand Structural Insulated Panel (SIP) with Oriented Strand Board (OSB) skins is popularly used in the building industry. Previous studies revealed that such SIP panels had weak impact resistant capacity and do not meet the design requirements to resist windborne debris impact specified in Australian Standard (AS/NZS1170.2:2011) for their applications in cyclonic regions. To increase the capacity of such SIP panels against windborne debris impact, basalt fibre cloth was used to strengthen the panel. Laboratory tests found that SIP strengthened with basalt fibre cloth was effective in increasing its impact-resistant capacity. This paper presents the development of a reliable numerical model to predict the impact responses of basalt fibre cloth strengthened SIP panel in LS-DYNA. The accuracy of the numerical model is verified by comparing the numerical and experimental results. The validated numerical model provides a reliable tool to predict basalt fibre cloth strengthened SIPs.

Experimental Investigation of Ice Mass Hydrodynamic Interaction With Offshore Structure in Close Proximity

2015 ◽  
Author(s):  
Tanvir Mehedi Sayeed ◽  
Bruce Colbourne ◽  
Heather Peng ◽  
Benjamin Colbourne ◽  
Don Spencer
Keyword(s):  
Hydrodynamic Interaction ◽  
Impact Load ◽  
Numerical Study ◽  
Numerical Models ◽  
Offshore Structures ◽  
Ocean Engineering ◽  
Offshore Structure ◽  
Area Of Interest ◽  
Close Proximity ◽  
The Impact

Iceberg/bergy bit impact load with fixed and floating offshore structures and supply ships is an important design consideration in ice-prone regions. Studies tend to divide the iceberg impact problem into phases from far field to contact. This results in a tendency to over simplify the final crucial stage where the structure is impacted. The authors have identified knowledge gaps and their influence on the analysis and prediction of iceberg impact velocities and loads (Sayeed et. al (2014)). The experimental and numerical study of viscous dominated very near field region is the main area of interest. This paper reports preliminary results of physical model tests conducted at Ocean Engineering Research Center (OERC) to investigate hydrodynamic interaction between ice masses and fixed offshore structure in close proximity. The objective was to perform a systematic study from simple to complex phenomena which will be a support base for the development of subsequent numerical models. The results demonstrated that hydrodynamic proximity and wave reflection effects do significantly influence the impact velocities at which ice masses approach to large structures. The effect is more pronounced for smaller ice masses.

scholarly journals Analytical and numerical study of the salinity intrusion in the Sebou river estuary (Morocco). Effect of the "Super Blood Moon" (total lunar eclipse) of 2015

2016 ◽  
Author(s):  
Soufiane Haddout ◽  
Mohammed Igouzal ◽  
Abdellatif Maslouhi
Keyword(s):  
Extreme Event ◽  
Transport Model ◽  
Numerical Study ◽  
Rapid Assessment ◽  
River Estuary ◽  
Lunar Eclipse ◽  
Salinity Intrusion ◽  
Salt Intrusion ◽  
Salinity Transport ◽  
The Impact

Abstract. The longitudinal variation of salinity and the maximum salinity intrusion length in an alluvial estuary are important environmental concerns for policy makers and managers since they influence water quality, water utilization and agricultural development in estuarine environments and the potential use of water resources in general. Total eclipses of Super-Moons are rare. According to NASA, they have only occurred five times in the 1900s – in 1910, 1928, 1946, 1964 and 1982. After the 28 September 2015 Total lunar eclipse, a Super-Bloodmoon eclipse will not recur before 8 October 2033. In this paper, for the first time, the impact of the total lunar eclipse (Super Blood Moon) on the salinity intrusion along an estuary is studied. The 28 September 2015 total lunar eclipse is focused by the study and the Sebou river estuary (Morocco) is taking as an application area. The Sebou estuary is an area with high agricultural potential, is becoming one of the most important industrial zones in Morocco and it is experiencing a salt intrusion problem. Hydrodynamic equations for tidal wave propagation coupled with (Savenije theory), and a numerical salinity transport model (HEC-RAS) are applied to study the impact of the total lunar eclipse on the salinity intrusion. Intensive salinity measurements during this extreme event were recorded along the Sebou estuary. Measurements showed a modification of the shape of axial salinity profiles and a notable water elevation rise, compared with normal situations. The two optimization parameters (Van Der Burgh's and dispersion coefficients) of the analytical model are estimated based on the Levenberg–Marquardt's algorithm (i.e. solving non-linear least squares problems). The salinity transport model was calibrated and validated using field data. The results show that the two models described very well salt intrusion during the total lunar eclipse day. A good-fit between computed salinity and measurements is obtained, as verified by statistical performance tests. These two models can give a rapid assessment of salinity distribution and consequently help to ensure the safety of water supply, even during such infrequent astronomical phenomenon.

Numerical and experimental study of steel wire mesh and basalt fibre mesh strengthened structural insulated panel against projectile impact

2017 ◽  
Vol 21 (8) ◽  
pp. 1183-1196 ◽  
Author(s):  
Qingfei Meng ◽  
Wensu Chen ◽  
Hong Hao
Keyword(s):  
Steel Wire ◽  
Impact Resistance ◽  
Wire Mesh ◽  
Wind Loading ◽  
Basalt Fibre ◽  
Windborne Debris ◽  
Steel Wire Mesh ◽  
The Impact ◽  
Debris Impact ◽  
Fibre Mesh

Extreme wind events caused damages and losses around the world every year. Windborne debris impact might create opening on building envelop, which would lead to the increase in internal pressure and result in roof being lift up and wall collapse. Some standards including Australia Wind Loading Code (AS/NZS 1170:2:2011, 2011) put forward design criteria to protect structures against windborne debris impacts. Structural insulated panel with Oriented Strand Board skin and expanded polystyrene core has been increasingly used in the building industry. Its capacity was found insufficient to resist the windborne debris impact in cyclonic areas defined in the Australian Wind Loading Code. Therefore, such panels need be strengthened for their applications in construction in cyclonic areas. In this study, impact resistance capacities of seven structural insulated panels strengthened with steel wire mesh and basalt fibre mesh were experimentally and numerically investigated. The impact resistance capacities were identified by comparing the damage mode, residual velocity and unpenetrated length of projectile after impact. Experimental results clearly demonstrated the enhancement of the impact resistance capacities of panels strengthened with steel wire mesh and basalt fibre mesh. Finite element model was developed in LS-DYNA to simulate the dynamic response of the structural insulated panels under windborne debris impact. The accuracy of the numerical model was validated with the testing data.

scholarly journals Analytical and numerical study of the salinity intrusion in the Sebou river estuary (Morocco) – effect of the “Super Blood Moon” (total lunar eclipse) of 2015

2016 ◽  
Vol 20 (9) ◽  
pp. 3923-3945 ◽  
Author(s):  
Soufiane Haddout ◽  
Mohammed Igouzal ◽  
Abdellatif Maslouhi
Keyword(s):  
Extreme Event ◽  
Transport Model ◽  
Numerical Study ◽  
Rare Event ◽  
River Estuary ◽  
Lunar Eclipse ◽  
Salinity Intrusion ◽  
Salt Intrusion ◽  
Salinity Transport ◽  
The Impact

Abstract. The longitudinal variation of salinity and the maximum salinity intrusion length in an alluvial estuary are important environmental concerns for policy makers and managers since they influence water quality, water utilization and agricultural development in estuarine environments and the potential use of water resources in general. The supermoon total lunar eclipse is a rare event. According to NASA, they have only occurred 5 times in the 1900s – in 1910, 1928, 1946, 1964 and 1982. After the 28 September 2015 total lunar eclipse, a Super Blood Moon eclipse will not recur before 8 October 2033. In this paper, for the first time, the impact of the combination of a supermoon and a total lunar eclipse on the salinity intrusion along an estuary is studied. The 28 September 2015 supermoon total lunar eclipse is the focus of this study and the Sebou river estuary (Morocco) is used as an application area. The Sebou estuary is an area with high agricultural potential, is becoming one of the most important industrial zones in Morocco and it is experiencing a salt intrusion problem. Hydrodynamic equations for tidal wave propagation coupled with the Savenije theory and a numerical salinity transport model (HEC-RAS software "Hydrologic Engineering Center River Analysis System") are applied to study the impact of the supermoon total lunar eclipse on the salinity intrusion. Intensive salinity measurements during this extreme event were recorded along the Sebou estuary. Measurements showed a modification of the shape of axial salinity profiles and a notable water elevation rise, compared with normal situations. The two optimization parameters (Van der Burgh's and dispersion coefficients) of the analytical model are estimated based on the Levenberg–Marquardt's algorithm (i.e., solving nonlinear least-squares problems). The salinity transport model was calibrated and validated using field data. The results show that the two models described very well the salt intrusion during the supermoon total lunar eclipse day. A good fit between computed salinity and measurements is obtained, as verified by statistical performance tests. These two models can give a rapid assessment of salinity distribution and consequently help to ensure the safety of the water supply, even during such infrequent astronomical phenomenon.

Numerical Study on Self-Consistency Centering Process of Periodic Symmetric Struts Support

2011 ◽  
Vol 462-463 ◽  
pp. 1373-1378
Author(s):  
Ji Zhe Hai ◽  
Mamtimin Gheni ◽  
Wei Bing Liu ◽  
Wei Chen ◽  
Lie Yu
Keyword(s):  
Thermal Deformation ◽  
Transfer Problem ◽  
Numerical Study ◽  
Numerical Models ◽  
Three Dimensional ◽  
Internal Flow ◽  
Three Dimensional Model ◽  
Temperature State ◽  
Before And After ◽  
The Impact

In this paper，the simplified three-dimensional model of Periodic Symmetric Struts Support (PSSS) was established, which is applied to a certain type of gas turbine. The software of computational fluid Dynamics (CFD) and the standard k-ε turbulence model are used in the numerical simulation．To simulate the coupling problems of fluid and solid，the numerical models by considering the heat transfer problem coupling with the solid and fluid have been developed．The internal flow field in PSSS was numerically simulated by an effective method for solving integrated coupling problems. The temperature field and thermal deformation rule of the PSSS was obtained. Through comparison coordinate values of the checked points before and after thermal deformation, the impact of thermal deformation on bearing center level height under temperature load was studied. The centering process of the PSSS at high temperature state was verified.

scholarly journals Evaluating the accuracy and uncertainty of atmospheric and wave model hindcasts during severe events using model ensembles

2021 ◽  
Author(s):  
Ali Abdolali ◽  
Andre van der Westhuysen ◽  
Zaizhong Ma ◽  
Avichal Mehra ◽  
Aron Roland ◽  
...  
Keyword(s):  
Extreme Event ◽  
Numerical Models ◽  
Model Performance ◽  
Ground Truth ◽  
Wave Model ◽  
Atmospheric Model ◽  
Stationary Source ◽  
Source Point ◽  
Spectral Wave Model ◽  
Model Ensembles

AbstractVarious uncertainties exist in a hindcast due to the inabilities of numerical models to resolve all the complicated atmosphere-sea interactions, and the lack of certain ground truth observations. Here, a comprehensive analysis of an atmospheric model performance in hindcast mode (Hurricane Weather and Research Forecasting model—HWRF) and its 40 ensembles during severe events is conducted, evaluating the model accuracy and uncertainty for hurricane track parameters, and wind speed collected along satellite altimeter tracks and at stationary source point observations. Subsequently, the downstream spectral wave model WAVEWATCH III is forced by two sets of wind field data, each includes 40 members. The first ones are randomly extracted from original HWRF simulations and the second ones are based on spread of best track parameters. The atmospheric model spread and wave model error along satellite altimeters tracks and at stationary source point observations are estimated. The study on Hurricane Irma reveals that wind and wave observations during this extreme event are within ensemble spreads. While both Models have wide spreads over areas with landmass, maximum uncertainty in the atmospheric model is at hurricane eye in contrast to the wave model.

scholarly journals A Rational Numerical Method for Simulation of Drop-Impact Dynamics of Oleo-Pneumatic Landing Gear

2021 ◽  
Vol 11 (9) ◽  
pp. 4136
Author(s):  
Rosario Pecora
Keyword(s):  
Numerical Method ◽  
Initial Conditions ◽  
Impact Load ◽  
Numerical Models ◽  
Landing Gear ◽  
Design Stage ◽  
Impact Dynamics ◽  
State Variables ◽  
Adopted Model ◽  
The Impact

Oleo-pneumatic landing gear is a complex mechanical system conceived to efficiently absorb and dissipate an aircraft’s kinetic energy at touchdown, thus reducing the impact load and acceleration transmitted to the airframe. Due to its significant influence on ground loads, this system is generally designed in parallel with the main structural components of the aircraft, such as the fuselage and wings. Robust numerical models for simulating landing gear impact dynamics are essential from the preliminary design stage in order to properly assess aircraft configuration and structural arrangements. Finite element (FE) analysis is a viable solution for supporting the design. However, regarding the oleo-pneumatic struts, FE-based simulation may become unpractical, since detailed models are required to obtain reliable results. Moreover, FE models could not be very versatile for accommodating the many design updates that usually occur at the beginning of the landing gear project or during the layout optimization process. In this work, a numerical method for simulating oleo-pneumatic landing gear drop dynamics is presented. To effectively support both the preliminary and advanced design of landing gear units, the proposed simulation approach rationally balances the level of sophistication of the adopted model with the need for accurate results. Although based on a formulation assuming only four state variables for the description of landing gear dynamics, the approach successfully accounts for all the relevant forces that arise during the drop and their influence on landing gear motion. A set of intercommunicating routines was implemented in MATLAB® environment to integrate the dynamic impact equations, starting from user-defined initial conditions and general parameters related to the geometric and structural configuration of the landing gear. The tool was then used to simulate a drop test of a reference landing gear, and the obtained results were successfully validated against available experimental data.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Numerical Simulation of the Impact of the Heat Source Position on Melting of a Nano-Enhanced Phase Change Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1425
Author(s):  
Tarek Bouzennada ◽  
Farid Mechighel ◽  
Kaouther Ghachem ◽  
Lioua Kolsi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Commercial Code ◽  
Tube Position ◽  
The Impact ◽  
Change Material

A 2D-symmetric numerical study of a new design of Nano-Enhanced Phase change material (NEPCM)-filled enclosure is presented in this paper. The enclosure is equipped with an inner tube allowing the circulation of the heat transfer fluid (HTF); n-Octadecane is chosen as phase change material (PCM). Comsol-Multiphysics commercial code was used to solve the governing equations. This study has been performed to examine the heat distribution and melting rate under the influence of the inner-tube position and the concentration of the nanoparticles dispersed in the PCM. The inner tube was located at three different vertical positions and the nanoparticle concentration was varied from 0 to 0.06. The results revealed that both heat transfer/melting rates are improved when the inner tube is located at the bottom region of the enclosure and by increasing the concentration of the nanoparticles. The addition of the nanoparticles enhances the heat transfer due to the considerable increase in conductivity. On the other hand, by placing the tube in the bottom area of the enclosure, the liquid PCM gets a wider space, allowing the intensification of the natural convection.

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