Cladding Panels Research Articles

Low-Damage Rocking Precast Concrete Cladding Panels: Design Approach and Experimental Validation

ABSTRACT This paper presents the development (concept, design, detailing, and fabrication) and experimental validation of a novel low-damage precast concrete cladding panel system that can accommodate significant inter-story drift demand through the rocking mechanism of the panels facilitated by smartly designed connections between the panels and the structural members. Two adjacent in-plane panels separated by ‘one-stage’ sealant joint were subjected to in-plane quasi-static cyclic drifts. The cladding system suffered no damage until 1.92% inter-story drift when the sealant tearing occurred. Furthermore, comparison with the seismic performance of traditional panel connections, reported in the literature, also demonstrated the system’s significantly improved seismic resilience.

Assessment of the Seismic Behavior of a Precast Reinforced Concrete Industrial Building with the Presence of Horizontal Cladding Panels

The latest earthquakes in Europe exposed some critical problems in the connections of cladding panels in industrial precast reinforced concrete (PRC) structures. These connections did not perform as desired, causing the panels to fall, leading to significant nonstructural damage that resulted in the loss of human life and significant socio-economic impacts due to the interruption of business. Furthermore, in addition to the behavior of the cladding system itself, it is still not clear to what extent it can influence the overall seismic performance of the main structure. Making use of a simplified macroelement, the present study assesses the seismic performance of commonly employed cladding-to-structure connections, as well as the interaction of cladding panels with industrial PRC buildings. The analyses were carried out considering a PRC building representative of a Portuguese industrial park, studied with and without cladding panels. The seismic behavior of the structure was assessed considering both nonlinear static and dynamic procedures.

Damping properties of innovative NiTi elements: development of proof of concept and demonstrators

Thanks to their functional properties, NiTi and NiTi-based shape memory alloys (SMAs) exhibit both pseudo-elastic and intrinsic damping ability finding applications in several fields. The use of these alloys in damping devices or systems allows the attenuation of different kinds of vibration such as noise or more intense oscillations. In this work, the damping behaviour of different NiTi semifinished products has been evaluated by means of dynamic thermomechanical measurements in order to have a preliminary indication for the integration of these SMA elements in damper demonstrators. The evolution of the internal friction parameter with respect to temperature, frequency and strain extent is evaluated. Moreover, some possible demonstrators’ concepts, i.e. a cladding panel, some dampers and a shock absorber, are proposed and characterized. The investigated SMA elements are a plain-woven mesh made of NiTi and steel thin wires, wave-shaped NiTi ribbons and NiTi single-turn wave springs. The elements have been thermally treated in order to achieve the required shapes and thermomechanical conditions. The perspectives and potential of these semifinished products in the field of damper devices are investigated by a preliminary characterization and discussed.

STUDY ON SEISMIC BEHAVIOR OF STEEL FRAME WITH ENERGY DISSIPATING CLADDING PANEL CONNECTIONS

An energy dissipating cladding panel connecting method for steel frames was proposed. In order to study the effect of this new kind of connecting method on the seismic behavior of the main structure, quasi-static cyclic tests were carried out on two steel frames with X- or U-shaped steel dampers as the energy dissipating connections and one bare steel frame counterpart. The quasi-static cyclic tests of the two kinds of dampers were carried out as well. The test results indicated that local buckling occurred on the X-shaped dampers during the fatigue loading stage, and the final failure was governed by the fracture of the core board; the U-shaped dampers only presented slight cracks in the fatigue loading stage and showed better fatigue performance; the hysteresis loops of the two kinds of dampers were plump and showed hardening stages, and the X-shaped damper showed a more obvious hardening effect owing to the membrane effect of the core board; the failure modes of the three steel frames were similar, and the damage mechanism of the steel frame was not altered by the cladding panels; cracks occurred on the cladding panel of GKJ-1 in the final loading stage due to the membrane effect of the X-shaped dampers, and the final failure mode of the specimen was governed by the broken of the connecting bolt between the cladding panel and the beam; no damage was observed in the U-shaped dampers and cladding panel of GKJ-2; the cladding panels with energy dissipating connections could increase the stiffness, strength and hysteresis energy of the steel frame.

Compression Experiment and Failure Analysis of Additive Manufactured Multi-Layer Lattice Sandwich Structure

The rapid development of additive manufacturing technology provides a new opportunity for the fabrication and research of multi-layer lattice sandwich structures, and thereby some excellent performances can be further discovered. Based on the manufacturing-experiment-analysis technical route, the failure mode of the additive manufactured aluminum multi-layer alloy lattice sandwich structure under quasi-static compression is systematically studied in this paper. Through the combination of experimental observation and finite element analysis, the complex failure mechanism of the multi-layer lattice sandwich structure is revealed. The results show that the multi-layer lattice sandwich structure under quasi-static compression conditions mainly manifests as a layer-by-layer failure mode of the internal lattice structure, which includes the yield, plastic buckling and material damage. At the same time, in comparison with the force–displacement curve and the structural deformation in the key locations, the analysis accuracy of the finite element model can be verified by the compression experiment. Based on the verified finite element model, the most significant influence of different face panel thicknesses, as well the rod radiuses and tilting angles on the energy absorption (EA) is identified via sensitivity analysis. Furthermore, size factors on the structural EA are revealed. This study can provide a helpful guidance for the design of multi-layer lattice sandwich structures in practical applications.

Failure Mechanism and Strength Prediction Model of T-Joint of Composite Sandwich Structure

Composite sandwich structures are widely used in many fields. T-joint plays a significant role in the composite sandwich structural connection. In this paper, a type of adhesive T-joint was manufactured and tested under bending and shearing load. According to the experiment, the finite element model was established to reveal the failure process. A strength prediction model was proposed based on the simulation. The results showed that the T-joint’s lower connector and the web’s lower face panel controlled its maximum load-bearing capacity, and the failure mode is the fiber compressive damage. The predicted ultimate bearing capacity of the T-joint showed a good agreement with the simulation, and the maximum relative error was less than 3%.

Design of Thermal Insulation Materials with Different Geometries of Channels.

Investigating the large number of various materials now available, some materials scientists promoted a method of combining existing materials with geometric features. By studying natural materials, the performance of simple constituent materials is improved by manipulating their internal geometry; as such, any base material can be used by performing millimeter-scale air channels. The porous structure obtained utilizes the low thermal conductivity of the gas in the pores. At the same time, heat radiation and gas convection is hindered by the solid structure. The solution that was proposed in this research for obtaining a material with porous structure consisted in perforating extruded polystyrene (XPS) panels, as base material. Perforation was performed horizontally and at an angle of 45 degrees related to the face panel. The method is simple and cost-effective. Perforated and simple XPS panels were subjected to three different temperature regimes in order to measure the thermal conductivity. There was an increase in thermal conductivity with the increase in average temperature in all studied cases. The presence of air channels reduced the thermal conductivity of the perforated panels. The reduction was more significant at the panels with inclined channels. The differences between the thermal conductivity of simple XPS and perforated XPS panels are small, but the latter can be improved by increasing the number of channels and the air channels’ diameter. Additionally, the higher the thermal conductivity of the base material, the more significant is the presence of the channels, reducing the effective thermal conductivity. A base material with low emissivity may also reduce the thermal conductivity.

Analysis of the Velocity Distribution in the Plenum Box with Various Entries

The ventilation system plays a crucial role in every building. Proper design and optimization of its operation increase the comfort of users due to efficient air exchange and at the same time control its velocity in the rooms. The aim of this paper is the analysis of the effect of plenum box entry on the velocity profile concerning the diffuser face panel. This issue may sometimes be ignored at the design stage but can significantly affect the airflow from the diffuser and consequently increase the risk of draft. The results of the PIV experimental measurements and numerical simulations concerning various entries of the plenum box (top and side) were investigated in this study. The measurements were used to develop the mathematical and numerical models, which were then used to assess the effect of localization of the spigot of the plenum box on its operation. The numerical analysis was carried out on plenum boxes with the air diffuser with a face panel composed of square grid perforations. Analyses show that the entries significantly affect both the way of air distribution inside the plenum box and the profile of the airflow and its velocity under the simulated air diffuser.

The Cross-Cultural Adaptation for Assessment of Chronic Illness Care Questionnaire Into Indonesian Version.

This study aimed to translate and adapt the Assessment of Chronic Illness Care (ACIC) version 3.5 into Indonesian version (ACIC-ID) and examine its validity and reliability as a practical tool for quality care measurement. A 3-phase process according to the World Health Organization Guideline for Instruments Translation and Adaptation was followed: (1) translation process by independent translators and adaptation by multidisciplinary expert panel review, (2) pretesting and face validity followed by cognitive interviewing with 10 general practitioners, and (3) final testing on 31 general practitioners for internal consistency and item-total correlation analysis. As a result, the content of ACIC-ID and the original version were conceptually equivalent. This version achieved excellent internal consistency (Cronbach's α 0.97), and item-total correlation was high (Pearson's r > 0.30) for the majority of items. The findings indicate that ACIC-ID is valid and reliable to identify areas that need to be improved in increasing the quality of chronic care.

A Note on the Structural Assessment of Perforated Panels used in Façade

Different materials such as glass and composite cladding panels are common in the façade industry due to their architectural appearance. The direct sun rays enter the building and might produce discomfort to the occupants, especially in office and institutional buildings. Nowadays, perforated panels are widely used in facades and becoming more popular in the middle east. These panels are a formal exploration inspired by the Islamic patterns used in traditional Mashrabiya. This paper provides an overview of the application of Mashrabiya "perforated panels" and present structural assessment using software codes such as Robot and SAP2000 for vertical and horizontal installed cases. These panels are fabricated in different sizes with different thicknesses depends on their applications and uses. In this paper, rectangular, square fixed at the roof and vertically fixed panels are assessed. These are usually supported by steel or aluminium tubes designed for a wind load specified by project specifications. The cases presented here for the perforated panels arechecked for the induced stresses and deflections obtained from the numerical model using shell elements. The adopted framing systems and fixing detailing has been found satisfactory according to different acceptance criterion. The paper gives helpful design tools for the façade engineers.

Seismic performance of a new energy dissipative cladding panel connection system for application in precast concrete frame structure

A precast concrete frame structure with a new energy dissipative cladding panel connection system (EDCPCS) based on the damping concept is proposed, in which line connection is adopted on the top of the panels as the load bearing connection and U-shaped steel dampers are installed at the bottom of the panels as the energy dissipation connection. The feasibility and reliability of this structural system are validated through a pseudo-static loading experiment on a full-scale substructure with an EDCPCS and a numerical investigation based on a multi-scale numerical simulation method. To further identify the damping effect at the overall structural level, nonlinear time-history analyses of two sets of structures are conducted using this simulation method, the response and damage control effects of the structures are initially clarified. Subsequently, the effects of critical design parameters (i.e., the stiffness ratio and yield force ratio) on the seismic responses of such structures are revealed based on 56 study cases. The findings can serve as a reference for the seismic design of high-performance structural systems with energy dissipative cladding panel connection systems.

Multi-Stripe Seismic Assessment of Precast Industrial Buildings With Cladding Panels

Following the empirical observation of widespread collapses of cladding panel connections of precast industrial buildings under recent seismic events, new design solutions have been developed in the framework of the European project SAFECLADDING, including isostatic systems effectively decoupling the seismic response of frame structure and cladding panels. The present paper is aimed at evaluating the seismic response and vulnerability of precast frame structures employing pendulum, cantilever, and rocking cladding connection systems. Within the framework of the research project RINTC–Implicit seismic risk of code-conforming structures funded by the Italian Civil Protection Department within the ReLUIS program, the seismic performance of a typical precast industrial building has been assessed with a probabilistic approach based on the results of static and multi-stripe dynamic non-linear analyses. The seismic vulnerability assessment of each structural system has been carried out with reference to life safety and damage limit states considering three sites of increasing seismic hazard in Italy. The effect of distributed panel mass modeling vs. more common lumped mass modeling has been analyzed and critically commented based on the results of demand over capacity (D/C) ratios. Moreover, biaxial seismic D/C ratios have been evaluated for realistic strong hinge connections for cladding panels.

Investigation of the Rate of Vacuum-Conductive Drying of Wood-Particle Panels Based on Polyvinyl Alcohol

Wood composites are promising construction and finishing materials that offer the best properties of both wood and polymers. With the industry's need to use low-toxic adhesives in view, one of the ways to ensure the environmental friendliness of composites is the use of polyvinyl alcohol as a binder. In this respect, in order to streamline production, both in terms of reducing energy consumption and improving the quality of the final product, it is vital to choose the drying rate when pressing panels. The paper presents the results of a study of the process of vacuum-conductive drying of eco-friendly polyvinyl alcohol (PVA)-based wood-particle material. It was found that the composite samples with a PVA content of 40% in terms of physical and mechanical parameters (ultimate bending strength and ultimate tensile strength perpendicular to the panel face) fully comply with the established standards. The study provided the values of drying rate depending on 5 factors. The multi-factor regression analysis method was used to derive equations that determine the drying rate of polyvinyl alcohol-based wood-particle panels for two humidity intervals (above and below the cell walls humidification limit), taking into account the properties of different classes of bodies that make up the composite.

Comparitive Studies of Futuristic Optimisezed and Regular Solar Panels with Windload Effects on Solar Farms, Solar Panels at High Altitude for Free Green Solar Energy

Solar energy is one of the most promising green and eco-friendly renewable energy out of the wind and other non-conventional energies. In nature, we have abundance of solar energy, due to this there is a significant attention on capturing the solar energy by photovoltaic systems in recent years. Photovoltaic energy conversion is most harnessing renewable energies for different communities especially in developing countries like India. The efficiency decrease is not only due to the shadows of buildings, but also due to birds, lack of sunlight and also wind effect on solar panels which will decrease efficiency and damage the total panels or array of panels. In this work, two different analyses are carried out with changing wind velocities and angle. The aerodynamic effects on the panels were investigated by varying the orientation of panels from 0 to 180 degrees and two different wind speeds of 5m/s and 25m/s. Initial angle of 0 degrees which is normal to the flow direction is solved for two different wind speeds of 5 m/s and 25 m/s and followed by changing the orientation of panels from 0 to 180 degree inclination to investigate the aerodynamic effects on the panels. Depending on the results obtained a futuristic panel design will be proposed which can generate optimum power and also aerodynamically effective. This current study indicates that the pressure distribution on the front face of the solar panels, which are aptly suitable to design optimized solar panel shapes.

Seismic Retrofitting Solutions for Precast RC Industrial Buildings Struck by the 2012 Earthquakes in Northern Italy

In 2012, the North of Italy was hit by a seismic sequence characterized by two main events occurred on May 20 and 29 with MW = 6.1 and 6.0, respectively. Those earthquakes were particularly severe toward precast Reinforced Concrete (RC) structures not designed for seismic resistance. In the past years, the authors implemented a database collecting damage data and typological information on the industrial buildings struck by the Emilia earthquakes. That database was used to develop empirical fragility curves, which highlighted the considerable vulnerability of precast buildings conceived in accordance with pre-seismic code provisions. More recently, the interventions of seismic retrofitting on the same buildings, funded by the Emilia-Romagna region and designed by engineers which were directly hired by the companies, were examined in detail and critically revisited. A selection of these interventions is presented in this paper, which analyzes the effectiveness of the various retrofitting solutions, with a specific attention to the force transfer mechanisms between existing structures and strengthening systems. The interventions are divided between column strengthening (based, for example, on RC or steel jacketing) and interventions aimed at providing the building with a suitable earthquake resistant system (based, for example, on either the use of the existing cladding panels or the implementation of new bracing systems). Graphical representations of the analyzed solutions with the relevant construction details are provided.

Shaking table study on the influence of ground motion frequency on the performance of MSE walls

Three shaking table tests were carried out to investigate the influence of loading frequency on seismic performance of MSE walls constructed with full-height panel facing. Results of this study provide quantitative results on how base excitation frequency in combination with base acceleration amplitude could influence the dynamic response of these MSE walls relative to their deformations, earth pressures, acceleration amplifications and connection loads. Results indicate that model walls responded primarily in tilting mode. However, base sliding could also occur as an additional deformation mode at larger base excitation amplitudes, and at frequencies that are closer to the fundamental frequency of the wall, resulting in significant connection loads and other response characteristics. Findings of the study are compared with results from other studies and recommendations in design guidelines, as applicable.

Compression behavior of a novel sandwich structure with bi-directional corrugated core

A novel sandwich structure with bi-directional corrugated core is designed and manufactured by 3D-printing. Initial attention focuses on the compression response and failure modes of this new structure. An analytical model is developed and verified by experimental and finite element methods (FEM). As a comparison, compression properties of the conventional sandwich structure are also tested under compression loading. Results show that the corrugation bucking and fracture are the main failure modes in the flatwise compression. However, the loading in edgewise direction is mostly supported by face panels, and obvious deformation is not observed. There is no debonding between the face panels and corrugated core under the continue loading, which means a well-bonding quality is achieved. The predicted results by analytical model show good agreements with those by FEM and experimental method. It has been proved that the stretching deformation is dominating in the deformation mechanism of flatwise compression. As for the edgewise compression, it finds that the corrugations paralleled to the loading direction are the main load-bearing structure. This novel sandwich material with bi-corrugated core owns better compression properties than the conventional one with single-corrugated core.

Dynamic response of sandwich beam with star-shaped reentrant honeycomb core subjected to local impulsive loading

The star-shaped reentrant honeycomb produces lateral shrinkage but also rotation under compression. With the consideration of such interesting deformation characteristics, the dynamic deformation evolution of the sandwich beam with star-shaped reentrant honeycomb core (SSRHC) was carried out for the first time. In this experiment, the aluminum foam projectile was used to produce local impulsive loading on the sandwich beam to research failure/deformation modes and deformation evolution of the SSRHC. The experimental results demonstrated the simultaneous shrinking and rotating deformations in the core. Finite element model (FEM) was employed to capture the dynamic mechanical response of panels and SSRHC on account of experimental results. Numerical results illustrated that the face panel moved toward the loading area in the early stage of impact, and local shrinkage or expansion was found within different regions of the star honeycomb cores during the entire compression process. In addition, it was found that the rotational deformation of the star honeycomb cells mainly occurred in the local indentation stage of the sandwich beam.

Cladding panel material as the basis for the typological variety of hinged facade systems

  The article discusses the variety of facing panels of hinged façade systems. Typological classification was made on the basis of a variety of materials used for facing panels. The author identifies 6 groups of materials: clay, wood, cement, titanium dioxide, metal, special components. Analysis is conducted on the 18 names of facing panels according to the following characteristics: cladding material, exterior, image application technology, weight in kg / m2, attachment, durability, and manufacturer. The article determines 6 criteria and 2 requirements for ventilated facades. Based on the typology of the material, the author outlines advantages and disadvantages of certain types of facing panels. The article determines the criteria and requirements set for ventilated facades. Leaning on the provided typology of material, the advantages and disadvantages of individual types of facing panels for hinged façade systems are indicated. The relevance of this research is substantiated by the growing need for modern technologies and means to make buildings look architectural and expressive due to an assortment of combinations of facing materials in hinged ventilated systems.  The study reveals a wide variety of characteristics and types of facing panels. The market offer fully reflects the modern production technology capabilities with regards to construction materials. Despite a number of restrictions imposed by the normative acts, facing panels fully meet all the requirements, as the construct of hinged façade panels in general. Thus, is safe to say that facing panels fully satisfy the market demand. Titanium dioxide panels purify the air, which is in line with the current environmental trends contributing to emission reduction and environmental cleanup.

A Review and Scientometric Analysis of Global Research on Prefabricated Buildings

Prefabricated building has become one of the most significant research directions in the architecture, engineering, and construction (AEC) industry and has attracted a large number of scholars and practitioners in recent years. However, few studies have conducted a systematic review on the development of prefabricated building research around the world. In this study, the scientometric method is used to analyze the literature on prefabricated buildings in the past ten years through analysis of co‐authors, co‐words, and co‐citation. From the Web of Science (WOS) core collection database, a total of 1224 articles were collected for statistics and analysis. The analysis results indicated that Bruno Dal Lago obtained the maximum number of co‐citations, and the most significant country/region and research institution in prefabricated building research were China and Tongji University, respectively. It was also found that engineering, civil engineering, and construction and building technology were the top three subject categories that prefabricated building research belonged to. Among all the keywords of the collected articles, citation bursts were received by “cladding panel,” “precast concrete,” and “project.” Moreover, there were 11 co‐citation clusters identified from the articles, and their themes included precast structures, waste management, progressive collapse, delay, precast facades, carbon reduction, laser scanning, and prefabricated residential building. This paper is expected to provide researchers and practitioners in this field a detailed and in‐depth understanding of the trend and status of global research on prefabricated buildings.