Cladding Panels Research Articles

The Study of Solar Incident on Planar Surface for Kinetic Art

In future, renewable energy will become mainstream global energy source because it flows all the time, also the solar energy. The sun always directly emits light through the earth, depending on how we utilize it. The study will fill the gap that the most of photovoltaic panel facing to the same direction against solar incident for maximum efficiently. It would be better if photovoltaic appliance to have aesthetic and capability in the same time. But changing planar surface angle for artistic purpose also need to consideration of efficiency for solar energy. The purpose of this study is to explore the most appropriate angle of solar incident that impacts directly to the planar surface, which will leads to gain maximum electric energy from photovoltaic cell. The variation angle of planar surfaces will be discovered could possibly produce energy to be applied for any purposes. The additional sources of other renewable energy gadgets may install to generate more electric power. These planar surfaces can be composited together into many new shapes and forms for researcher to create more impressive artwork. In this study, the chosen material was Monocrystalline solar cell (mono-Si) to generate energy, wood and glass for kinetic sculpture. The procedures of study were as follow: 1. Specific location by Latitude will be achieved I. Altitude II. Seasons III. Sunlight direction IV. Sunrise and Sunset time 2. Calculate Solar radiation from each Photovoltaic cell for energy gain. 3. Compares output energy and mechanic usage for Kinetic Art 4. Increases capability of solar incident by improving angle of planar surface or multiply. Results of this research will be the search of artistic identity in art forms, it will be guideline for designers to develop potential Kinetic arts and or further creative works.

Experimental Study on Composite Light-weight Microporous Concrete Cladding Panels

A new type of composite light-weight microporous concrete cladding panel was developed, with the compound function of retaining and heat preservation. Two specimens of the new cladding panel and connection detailing were made for out-of-plane bending experiment. The results indicate that the new cladding panel and its connection detailing are of sufficient stiffness, bearing capacity and deformability under wind load and out-of-plane seismic action.

Experimental and numerical investigation on coal drawing from thick steep seam with longwall top coal caving mining

Steep coal seam mining activities will frequently occur during the next few decades in China. In this study, both experimental and numerical methods are employed to investigate the coal drawing from thick steep seam with longwall top coal caving mining. A series of analyses is performed to investigate the features of the drawing body, the distribution of top coal recovery ratio and the shape of the rock flow under steep conditions. The results indicate that the drawing body of top coal develops prior to upper side of the panel face obviously, and the top coal in the central part of the panel has a higher recovery ratio than that in the lower and upper parts in steep coal seam with caving mining method. The flow paths of the fragmented top coal are nearly straight lines moving towards the drawing window, and the fastest path maintains a constant angle with the plumb line. The spatial shape of the rock flow indicates “bidirectional asymmetry,” which results from the presence of the shield beam and dip angle of the coal seam; thus, this is the root cause of the appearance of the drawing body’s prior development towards the upper side of the panel. The field observation data indicates the same distribution of top coal recovery as that in the physical experiment and numerical simulation. Furthermore, suggested measurements are proposed to improve top coal recovery in steep seam mining based on the engineering practice of Dayuan coal mine.

Post-fire mechanical performance of modular GFRP multicellular slabs with prefabricated fire resistant panels

Abstract Investigation of the post-fire mechanical performance of large-scale glass fibre reinforced polymer (GFRP) structures assembled with prefabricated fire resistant panels is reported in this paper. The GFRP structures were four modular web-flange multicellular sandwich slabs fabricated of face panels and web box sections using adhesive bonding. Three sandwich slabs had fire resistant panels installed, either glass magnesium (GM) board, gypsum plaster (GP) board or calcium silicate (CS) board, at the outer face of the lower face panel using screws. These three specimens were exposed from the underside to an ISO 834 fire curve for up to 70–90 min and then cooled to room temperature. Subsequently they were tested in four-point bending and compared to the fourth specimen without fire exposure. The composite action between face panels and web box sections is discussed and the failure modes of specimens are identified. Importantly, the effects of fire resistant panels on the post-fire mechanical performance of the GFRP multicellular assemblies are highlighted and quantified. Analytical modelling is further developed to estimate post-fire bending stiffness and load-carrying capacity considering the recovery of resin after glass transition but before decomposition and the contribution from the remaining continuous rovings for the decomposed GFRP materials, with satisfactory agreement with the experimental results. It was demonstrated that the specimen with the glass magnesium board showed superior post-fire mechanical performance, with more than half of the post-fire stiffness and capacity remaining after 90 min fire exposure.

Full-scale mechanically stabilized earth (MSE) walls under strip footing load

This study analyses two full-scale model tests on mechanically stabilized earth (MSE) walls. One test was conducted with a rigid and one with a flexible wall face. Other parameters were the same in these two tests, like the number and type of geogrid layers, the vertical distance between the layers and the soil type. The loads and strains on the reinforcement are measured as function of the horizontal and vertical earth pressure and compared with analytical models. Specifics regarding the behavior of the geogrids under the compaction load during the construction of the model and under strip footing load are included in the study. Results are compared with AASHTO and the empirical K-stiffness method. In this study, an analytical method is developed for the MSE walls taking into account the facing panel rigidity both after backfill construction and after strip footing load. There is good agreement between the proposed analytical method and the experimental results considering the facing panel rigidity. The results indicate that the tensile force on reinforcement layers for rigid facing is less than the flexible facing. The maximum strains in the reinforcement layers occurred in the upper layers right below the strip footing load. The maximum wall deflection for the flexible facing is more than for the rigid facing. The maximum deflection was at the top of the wall for the rigid facing and occurred at z/H = 0.81 from top of the wall for the flexible facing.

Novel development of dynamic behavior of carbon fiber reinforced polymer sandwich panels with stepwise graded adhesive layer

Purpose The purpose of this study is to focus on the developments of carbon fiber reinforced polymer (CFRP) panels with stepwise graded properties on adhesive layer. The various arranges of the graded properties of the adhesive layer have been checked according to experimental results of the literatures and based on applicability. Design/methodology/approach The finite element (FE) models and experimental modal tests of the manufactured CFRP sandwich panel specimens have been investigated. The core thickness, core density and orientation of the fiber direction of the sandwich panel face – sheets have been parametrically checked based on modal behavior. Two fully free and fully clamped boundary conditions (BC) have been checked in stepwise graded adhesive zone (SGAZ) cases and first five non-zero natural frequencies (NF) have been compared. Dynamic response of the SGAZ includes modal analysis and transient dynamic loading have been performed numerically with ABAQUS 6.12 well-known FE code. Findings The first non-zero NF of SGAZ Case 4 was 11.69 per cent higher than homogenous Case 2 and 7.06 per cent lower than Case 1 in fully free boundary conditions. A total of 26.38 per cent is the greatest discrepancy between fist five non-zero NFs of all cases with two BCs (Case 1 vs Case 2 in fully clamped BC). Maximum structural damping behavior and minimum stress picks have been studied during transient dynamic loading analysis of CFRP panel with SGAZ. SGAZ Case 3 (middle adhesive with lower modulus) has increased the maximum structural damping while reducing the minimum out of plain tip displacements during transient dynamic loading by 111.26 per cent in comparison with homogenous Case 2. Also, Case 3 has reduced the Mises stress picks on the adhesive region by 605.68 per cent. Practical implications Making a stepwise graded adhesive region (without any added mass) has been shown that it is a novel and useful way to achieve a wide range of stiffness on CFRP panels. Originality/value Development of the sandwich panels with various stiffness and damping properties.

Experimental investigation of the response of precast concrete cladding panels with integrated connections under monotonic and cyclic loading

One major issue in the design of precast structures against earthquakes is the importance of cladding connections on the overall response. In the present work, an experimental investigation on the monotonic and cyclic behaviour of fixed panel connections, also referred as ‘integrated’ connections, is reported. The extensive experimental program was performed at the Laboratory for Earthquake Engineering of the National Technical University of Athens, Greece, within the framework of the FP7 European project SAFECLADDING, and aimed at the investigation of the behaviour of several types of connections materialized with vertical reinforcement bars, referred as ‘rebar’ connections, or steel mechanisms of two types: ‘wall shoe’ and ‘steel plate’. The results show that rebar and wall shoe connections can attain large ductility and strength, but with significant pinching for large lateral displacements, due to the plastic deformation of the connections’ rods that can lead even to residual joint opening. When this happens, apart from the horizontal slip that can occur, the energy dissipated decreases, as evident from the corresponding normalized energy dissipation capacity curves of the tested specimens. The damage to the panels observed during the tests was generally limited, except of large drifts combined with strong connections, and the overall failure was determined by the failure of the connectors.

Analysis of the performance of adhesively bonded corrugated core sandwich structures using cohesive zone method

Stress analysis of adhesively bonded joints of sandwich structures is more complex. Only a few research works have studied this subject. The major obstacle is finding the stress distribution at the adhesive layer of sandwich structures under different loading conditions. This paper presents a study on stress distribution at the adhesive joints of the corrugated sandwich structure subjected to three-point bending using the cohesive zone model. Firstly, three cases of sandwich models with different types of glue on both longitudinal and transverse loading directions were calculated using cohesive zone model, and then the corresponding experiments were carried out and compared to prove the FEM results to validate the results through both load–displacement curves and failure deformation modes. Secondly, the cohesive zone model simulation was used to obtain the detailed stress distribution at the bonding joint with the effect of four major geometrical parameters: adhesive layer thickness, corrugated panel thickness, face panel thickness and adhesive joint width. Lastly, the results of stress analysis showed that the stress distribution is not uniform and is highly affected by the bonding joint's geometrical parameters, adhesive layer thickness and adhesive joint width.

Evaluation of out‐of‐plane seismic performance of column‐to‐column precast concrete cladding panels in one‐storey industrial buildings

SummaryRecent earthquakes in Italy (L'Aquila 2009 and Emilia 2012) highlighted the vulnerability of precast cladding panels, typically associated with a connection system not designed to account for displacement and rotation compatibility between the panels and the supporting structure. Experimental investigations were performed in the past to investigate the in‐plane performance of cladding panels and design recommendations have been made accordingly; however, in the case of out‐of‐plane seismic loads, the load demand is commonly evaluated in the design practice by means of formulations for nonstructural components.This paper summarizes the results obtained from parametric analyses conducted to estimate the out‐of‐plane load demand in column‐to‐column cladding panels typical of one‐storey commercial and industrial buildings. Empirical equations suitable for both new and existing panels are proposed and compared with the design equations given in Eurocode 8 and ASCE 7. The paper also considers the effects of the development of plastic hinges at the column base and of the roof flexibility on the load demand in panel‐to‐column connections. The roof flexibility may generate the torsion of the panels; consequently, an analytical procedure to account for such effects is proposed. Finally, general design recommendations are made.

Study of the process of shape-formation of ribbed double-curvature panels by local deforming

Accuracy of double-curvature ribbed panels obtained by multipoint local deformation using the proposed procedure of distribution of local actions was studied. As equipment for local action, an innovative die was used enabling the rib portion to be bent together with the adjacent sheet in both directions and perform shrinking (shortening) or stretching (extension) of this section along the rib axis. Features of making double-curvature panels with an irregular internal structure using local shaping by bending and shrinking (stretching) were considered. A procedure was described for calculating the number of local actions necessary to obtain panels of the required shape and size. The results obtained in testing the procedure for distributing local actions on samples and the full-scale panel of an aircraft fuselage of a transport category were presented. An experimental study of accuracy of the obtained dimensions by comparison of measurements of height of the points in the shaped panel with calculated values of the panel coordinates was carried out. Experimental studies of accuracy of the panel face shape showed that the maximum deviation after applying the calculated actions was 1.48 mm for longitudinal sections and 1.67 mm for transverse ones. Individual deviations of the shape, for example deviations of the free edges and curvature near the ends of the ribs required refinement works after which the shape deviations did not exceed 0.3 mm. Basic recommendations were elaborated for making double-curvature (biconvex, biconcave, convexo-concave and concavo-convex) panels.

Wind Fragility for Honeycomb Roof Cladding Panels Using Screw Pull-Out Capacity

Wind Fragility for Honeycomb Roof Cladding Panels Using Screw Pull-Out Capacity

Thermal insulation materials from renewable resources: thermal and hygric performances

The European ISOBIO project aims to develop new bio-based building insulating materials which contribute to reduce environmental impacts of buildings. The developed materials shall have low embodied energy and low carbon footprint and shall contribute to reduce energy needs of buildings ant to ensure high hygrothermal comfort of users. This study investigates the valuation of agro-resources as bio-based aggregates and as binding material to produce wholly bio-based composites. Two types of aggregates: hemp shiv and corn cob residues (obtained after alkali treatment on the corn cob), and five types of green binders are investigated. Specimens are produced to characterize thermal and hygric properties of developed composites and to identify the best mixture between aggregate and binder. They show interesting thermal and hygric properties. They have low thermal conductivity ranging from 0.067 to 0.148 W/(m.K) and depending on the mix (aggregate with binder). They are excellent hygric regulators (MBV >2 g/(m².%RH)). These results suggest that developed composites can be used as building materials but not for the same types of use. In fact, some composites would be more suitable for thermal insulating products and others would be better suited to indoor facing panels.

Centrifuge model study on geogrid reinforced soil walls with marginal backfills with and without chimney sand drain

The objective of this paper is to investigate the performance of geogrid reinforced soil walls with panel facing using marginal backfill with and without chimney sand drain subjected to seepage. A series of centrifuge model tests were performed at 40 gravities using a 4.5 m radius large beam centrifuge facility available at IIT Bombay. The results revealed that a geogrid reinforced soil wall with low stiffness geogrid and without any chimney drain experienced a catastrophic failure due to excess pore water pressure that developed in the reinforced and backfill zones at the onset of seepage. In comparison, a soil wall reinforced with stiff geogrid layers was found to perform effectively even at the onset of seepage. Provision of chimney sand drain effectively decreased pore water pressure not only at the wall toe but also at mid-distance from toe of the wall and thereby resulted in enhancing the wall performance under the effect of seepage forces. However, a local piping failure was observed near the toe region of the wall. The observed centrifuge test results were further analysed by performing seepage and stability analyses to evaluate the effect of thickness of sand layer in a chimney drain. An increase in thickness of sand layer in chimney drain was found to improve the discharge values and thereby enhancing the factor of safety against piping near the toe region. Based on the analysis and interpretation of centrifuge test results, it can be concluded that marginal soil can be used as a backfill in reinforced soil walls provided, it has geogrid layers of adequate stiffness and/or proper chimney drain configuration.

Use of static tests for predicting damage to cladding panels caused by storm debris

The impact by debris can result in extensive damage to building facades and roof coverings in extreme climate conditions such as windstorms and hailstorms. Damage can be in the form of denting on the surface of a metal cladding panel, which is controlled by the amount of force developed at the point of contact between the debris object and the surface of the panel. Amid the lack of guidelines for assessing damage to the building envelope, it is common to conduct impact tests on a cladding specimen. Such tests often involve the use of a gas gun to fire projectiles; however, there are shortcomings with this approach as it is mostly undertaken to check compliance and to observe permanent damage to the specimen. This paper presents the use of quasi-static tests to simulate the impact induced damage to metal cladding in storm scenarios. The contact force value generated during the impact action is predicted using the two-degree-of-freedom system model so that the impact action can be applied in a quasi-static manner on an MTS machine to predict damage in the form of indentation or perforation. This experimental technique for predicting damage is illustrated and verified in this paper by conducting confirmatory impact experiments. The risk of damage to metal cladding caused by impact in storm scenarios could then be assessed with confidence without having to conduct repetitive impact testing involving accelerating projectiles onto specimens of metal cladding. This research provides designers with an accurate and cost effective means of quantifying impact induced damage on building facades, and allows system developers to adapt and utilise existing and new materials to develop innovative solutions for withstanding impact.

Lightweight Concrete Containing Phase Change Materials (PCMs): A Numerical Investigation on the Thermal Behaviour of Cladding Panels

The use of phase change materials (PCMs) in building elements has gained increasing popularity in recent years because of the potential energy savings that result from the heat stored during variable temperature–time histories. This paper describes the results of non-linear numerical analyses on sandwich panels characterized by different geometry and consisting of an innovative concrete, i.e., lightweight concrete with aggregates containing PCMs. The amount of embedded PCMs has no equal in the literature, and this calls for a detailed assessment of its thermal performance within a typical building element. The heat transfer process inside the panels is modelled via finite elements in order to evaluate the effectiveness of the addition of PCMs with regard to insulation. The results show that adding PCMs may significantly reduce (by up to 20%) the energy required for cooling in the hot season, while the reduction of the energy required for heating in the cold season is lower (up to 10%). Moreover, there is a significant reduction in the instantaneous power required, both for heating and cooling.

Experimental Investigation on Steel W-Shaped Folded Plate Dissipative Connectors for Horizontal Precast Concrete Cladding Panels

ABSTRACTA dissipative connector device, consisting of a steel plate folded at right angle along three lines to get a W-shaped profile, is proposed for the safe fastening of the horizontal cladding panels of new or existing precast structures under seismic action. Experimental tests are carried out to characterize the hysteretic behavior of the connector device. Different technological features, restraint conditions, and loading protocols are considered. Nonlinear hysteretic models are validated against the results of pseudo-dynamic tests on a full-scale prototype of precast building with cladding panels. Guidelines for the design of the dissipative connector device are provided.

Damage modelling of aluminium panels impacted by windborne debris

Impact by flying debris in windstorms conditions has been a major contributor to damage to aluminium and other types of building facades. The damage so caused to cladding panels was mainly controlled by the amount of force that was developed at the point of contact between the debris object and the surface of the target. However, no codified design guidelines are currently available to quantify the required impact resistance of an aluminium panel for given storm scenarios. Current analytical expressions derived for analysing impact actions as reported in the literature are mostly based on the use of energy principles. The influence of the hardness of the debris object and the magnitude of the contact force has not been taken into considerations. Thus, the amount of deformation that is inflicted on the panel by the impact of a non-rigid projectile object can be over-stated. This paper presents an analytical expression that has been developed for estimating the severity of damage to the surface of a cladding panel (and to determine if leakage of rainwater from the panel can be resulted) for given mass of the debris object, velocity of impact, and importantly, parameters characterising the stiffness properties of the impactor object.

Longwall mining under gateroads and gobs of abandoned small mine

Due to the use of outdated mining technology or room and pillar mining process in small coal mines, the coal recovery ratio is only 10–25%. In many regions of China, the damage area caused by the small coal mines amounted to nearly one hundred square kilometers. Therefore, special mining techniques must be taken to reclaim the wasted resource in disturbed coal areas. This paper focuses on the different mining methods by analyzing the longwall panel layout and abandoned gateroad (AG) distribution in the abandoned area of Cuijiazhai coal mine in northwestern China. On the basis of three-dimensional geological model, FLAC3D numerical simulation was employed. The abutment pressure distribution was simulated when the panel face passed through the disturbed areas. The proper angle of the inclined face was analyzed when the panel face passed through the abandoned gateroads. The results show that the head end of the face should be 13–20m ahead of the tail end. The pillars on both sides of abandoned gateroads had not been damaged at the same time, and no large-area stress concentration occured above the main roof. Therefore, the coal reserves of disturbed areas can be successfully recovered by using underground longwall mining.

Experimental investigation on the influence of silicone sealant on the seismic behaviour of precast façades

Silicone sealant is usually interposed between panels of precast facades. In ordinary cladding panel configurations, relative sliding between panels occurs under lateral actions. The shear drifts and consequent stresses arising in the silicone strips may lead to a significant increase of the load demand in the cladding panel connections and affect the seismic behaviour of the structural system. This paper presents the results of experimental tests and numerical analyses carried out to clarify the role of the silicone sealant on the seismic response of precast structures with cladding panels. An experimental campaign including monotonic and cyclic tests on both silicone strips applied to small concrete blocks and two panel sub-assembly sealed with silicone, has been developed at Politecnico di Milano. Furthermore, cyclic and seismic pseudo-dynamic tests on a full-scale prototype of precast building with cladding panels sealed with silicone, have been performed at the Joint Research Centre of the European Commission. The results of the experimental tests are presented and compared with the results of numerical simulations. Some recommendations for seismic design of precast frame structures with cladding panels, considering the effect of silicone sealant, are finally provided.

Seismic response of precast structures with vertical cladding panels: The SAFECLADDING experimental campaign

The SAFECLADDING Project was aimed at improving the connection systems between cladding panels and precast RC buildings in seismic-prone areas. Three design criteria have been assessed: isostatic, dissipative and integrated. They can be realised using different strategies, which are represented by several test setups within the experimental campaign.The paper describes the results obtained with vertical panels arrangement and the comparison with the bare frame, which is the reference for the current design practice that considers panels like non-structural elements. The mock-up and the test sequence were designed to assess all setups with a single frame structure. The mock-up was a one-storey building, made by two parallel frames with two bays and square columns, inserted into pocket plinths. The building was designed for earthquake actions according to the Eurocode 8. Each setup was assessed using increasing levels of action, either with cyclic or pseudo-dynamic tests. The latter were performed both for serviceability and ultimate limit states. The experimental programme for vertical-panels and the bare-frame arrangement involved ten different setups, resulting in a total of twenty-eight tests.As for the isostatic criterion, the results confirm that considering panels as simple masses without stiffness is far from the real system behaviour, even using apposite devices to uncouple panels and frame displacements. In fact, despite a previous and positive experimental qualification, several devices failed in operative conditions tests.Conversely, the integrated criterion requires to bear high loads, transferred by the frame through connections, which becomes the weak point for this configuration, as demonstrated by different failures of bolts and connections.The reliability of the dissipative criterion has been confirmed by twelve tests completed without any damage. This solution in fact combines lower relative displacements with limited loads within connections, avoiding both the compatibility problems and excessive forces.