Exterior Panels Research Articles

Study on prefabricated composite shear wall cladding anti-shedding connection structure

Fabricated steel structure systems have undergone significant advancements. However, problems associated with exterior wall panel systems have become increasingly prominent, particularly the issue of exterior wall panel shedding. Three full-scale fabricated composite shear wall exterior panel components were designed and tested under quasi-static conditions. The failure sequence and characteristics of the exterior wall panels at different displacement angles, including their out-of-plane displacement and stiffness degradation, were evaluated to assess their seismic and connection performance in different building construction methods. The results indicated that drilling holes near the centre of autoclaved lightweight concrete (ALC) boards improved the seismic performance of wall panels. Long round holes in the ALC boards allowed the dissipation of sliding energy during the initial deformation of wall panels. Furthermore, wall panels with bonded anchorage connections for rockwool boards exhibited better seismic performance than those with pure anchorage connections. To verify the accuracy of the findings, a structural finite element model was established, and the influences of various parameters, such as the position of ALC board connecting bolts, length of ALC board holes, and bonding rate of rockwool boards, on the stress and deformation of the exterior wall panel system were analyzed. Based on the test results and finite element simulation analysis, an anti-shedding connection construction method was proposed.

The effect of temperature difference on bending of external panel walls

One of the most common structural systems of buildings intended for various purposes is a prefabricated panel system of factory-made elements assembled on-site. Single-layer structures made of lightweight concrete are widely used as envelopes of these buildings. In buildings operated under various climatic conditions, exterior wall panels, as well as other envelopes, are exposed to thermal deformations and, accordingly, changes in the stress-strain state. As the temperature changes, corresponding stresses and deformations occur across the thickness of the exterior panels. To analyze their values, the bending moments and support reactions of single-layer lightweight concrete panels of different length and thickness in the range of temperature differences from 0 °С to 65 °С have been calculated. It was found that the bending moments and support reactions of 1,500 mm long panels decrease as the thickness of the panels increases over the entire temperature gradient. The values of bending moments and support reactions of panels with length of 3,000, 4,500 and 6,000 mm decrease only when the temperature rises from 0 to 10 °С, in the rest of the range 15–65 °С – increase as the thickness of the panel increases due to the bending stiffness.

Evaluation of mechanical properties and Fick’s diffusion behaviour of aluminum-DMEM reinforced with hemp/bamboo/basalt woven fiber metal laminates (WFML) under different stacking sequences

This work examines the mechanical properties and structural aspects of Al-Hybrid fibre metal laminates (HFMLs) reinforced with fibres from basalt, hemp, and bamboo, including commercial-grade Al6061 alloy mesh (Al-DMEM). Compression moulding of sustainable fibres into various stacking configurations, such as BAlB, BHAlHB, and BBbAlBbB, was required for fabrication. Using cutting-edge methods like SEM and EDX for microstructure investigation, extensive testing was carried out, including tensile, flexural, impact, interlaminar shear, hardness, and water absorption tests. Basalt/Bamboo/Aluminum/Basalt (BBbAlBbB) was the FML configuration with the best mechanical parameters, showing Vickers hardness (24.23 MPa), tensile strength (44.537 MPa), flexural strength (218.24 MPa), and impact resistance (2.01 J) (59.982 HV). In addition, BAlB showed 83.9 % Vickers hardness, 41.7 % flexural strength, and 90.4 % tensile strength of BBbAlBbB samples. BHAlHB displayed 92.9 % of the flexural strength, 65.3 % of the tensile strength, and 93.7 % of the Vickers hardness of BBbAlBbB. Bamboo is hydrophobic by nature, so adding bamboo fibres to BBbAlBbB significantly boosted its resistance to moisture. This study highlights the potential of hybrid FMLs as high-performance, eco friendly materials that are particularly well-suited for applications in interior and exterior panels for micro-mobility (E-vehicles), with AL-DMEM reinforcement offering significant benefits like improved fibre bonding and structural integrity.

Investigation of production conditions of interstitial-free steels in electric arc furnace

The iron and steel industry has had a strategic importance throughout history. In recent years, with the development of technology and sectoral competition, new investments have been investigated. One of them is Interstitial-Free (IF) steels. Interstitial-Free Steel, containing very small amounts of carbon and nitrogen, is used in the production of automotive interior and exterior panels. IF steel structures have high formability. This feature has been obtained by removing interstitial atoms such as C and N in vacuum degassing method. In addition, remaining of these elements can be stabilized in steel by adding Ti and/or Nb. After the steel production process is completed, the slab is heated to a certain temperature in the heating furnace. The finishing and coiling temperatures are also important factors in determining the deep-drawing capability. These parameters help in obtaining the coarse TiC and NbC precipitates and the high r value, which is an important indicator of fine-grained structure, high ductility and formability. In this study, the effect of process parameters on IF steels in electric arc furnace steel production, secondary metallurgy processes and hot rolling are explained. Also, the effect of microstructures of steel samples with different chemical compositions and thicknesses on mechanical properties was investigated. In addition, the samples taken from the hot rolled coil were examined under scanning electron microscope (SEM), and texture analysis was performed with electron backscatter diffraction (EBSD) technique. Particularly, the microstructure investigations have shown that Ti and/or Nb is the critical element in terms of ensuring the formability, so interstitial atoms are not formed

Calculating and Analyzing Carbon Emission Factors of Prefabricated Components

The construction industry’s carbon emissions have a considerable impact on the environment, and all countries have pledged to reduce them to achieve low-carbon transformation. The use of prefabricated components is widely recognized as a crucial measure for mitigating carbon emissions. However, there is a scarcity of existing data on the carbon emission factors of prefabricated components (CEFoPC), and few studies have focused on calculating and reducing their carbon emissions. This study presents a novel approach to calculating CEFoPC, which involves analyzing the production process, defining the carbon emission range, identifying the sources of carbon emissions, and establishing measurement equations for the carbon emissions of prefabricated components. The proposed approach is demonstrated using six typical prefabricated components in Nanjing, China, namely, prefabricated exterior and interior wall panels, stairs, laminated panels, balconies, and air conditioning panels. After decomposing the carbon emission factors and exploring carbon emission reduction strategies, the findings suggest that the production and transportation of raw materials are the primary contributors to carbon emissions associated with prefabricated components. Additionally, the most effective carbon emission reduction strategy involves the use of green and recycled raw materials. Furthermore, the framework for calculating CEFoPC proposed in this study is considered a significant contribution, as it can facilitate future research and the enrichment of carbon emission factor databases.

Teijin Automotive Technologies supplying exterior components on new Lotus Emira

On April 26, 2023, Tejin Automotive Technologies announced that exterior of the new Lotus Emira is made possible, in part, by the advanced composite exterior panels provided by Teijin Automotive Technologies. Specifically, Teijin Automotive Technologies is providing the right- and left-hand doors; right- and left-side rear quarter panels, and the inner, outer and lower shells of the tailgate.

Mathematical approach of fiber optics for renewable energy sources using general adversarial networks

It is significantly more challenging to extend the visibility factor to a higher depth during the development phase of a communication system for subterranean places. Even if there are numerous optical fiber systems that provide the right energy sources for intended panels, the visibility parameter is not optimized past a certain point. Therefore, the suggested method looks at the properties of a fiber optic communication system that is integrated with a certain energy source while having external panels. A regulating state is established in addition to characteristic analysis by minimizing the reflection index, and the integration of the general adversarial network (GAN) optimizes both central and layer formations in exterior panels. Thus, the suggested technique uses the external noise factor to provide relevant data to the control center via fiber optic shackles. As a result, the normalized error is smaller, boosting the suggested method's effectiveness in all subsurface areas. The created mathematical model is divided into five different situations, and the results are simulated using MATLAB to test the effectiveness of the anticipated strategy. Additionally, comparisons are done for each of the five scenarios, and it is found that the proposed fiber-optic method for energy sources is far more effective than current methodologies.

Thermal performance and thermal transmittance prediction of novel light-gauge steel-framed straw walls

Thermal bridges in light-gauge steel-framed exterior walls lead to more winter heat loss, summer heat gain, and building pathologies generated by moisture condensation and mould growth, which are unfavorable for building energy efficiency and service life of sheathing panels. A novel light-gauge steel-framed straw wall with a nonmetallic broken bridge layer was proposed, which consists of two sheathing panels on both sides of the wall, two frames, a middle sandwich layer, and two kinds of fasteners. The environmentally friendly straw boards including paper straw board (PSB) and wheat straw strand board (WSSB) were used as middle sandwich layer and exterior panel respectively. This study focuses on the thermal performance and the prediction method of thermal transmittance (Um-value) for such walls. Tests using the temperature control box-heat flux meter method were carried out for three representative walls with different configurations. Based on analyses of the temperature and heat flux density distributions, it is found that the broken bridge layer and the airspaces between the sheathing panel and the track or the bracing can effectively reduce the thermal bridge effect, with the relative effects less than 5%. Based on the test results of the Um-values, different wall configurations were matched with the feasible climate zones on the basis of energy efficiency design. After the validation by comparing with the test results in terms of temperature, heat flux density, and Um-value, the numerical study was carried out to broaden the feasible climate zones, and walls with improved configurations were proposed and analyzed. The results show that, by replacing the unventilated airspaces with the expanded polystyrene (EPS) boards, a maximum improvement in thermal performance reaches 74.89%. Thus, the feasible climate zones of the walls have been extended to the severe cold zone. Finally, a thermal transmittance prediction methodology based on the calculation method specified in European Standard EN ISO 6946-2017 in conjunction with the modified method considering thermal bridge effect was used to predict the Um-‍values of the improved walls. This study provides a new design strategy with nonmetallic broken bridge layer to reduce the unfavorable influence of thermal bridges in light-gauge steel-framed walls. Such a design strategy contributes to less energy consumption in addition to making full use of agricultural waste straw, which plays a positive role in the development of green buildings.

Analytical and parametric analysis of interface stress behaviour in nanoclay/polymer composite

Nowadays, nanoclay-reinforced polymers are one of the most widely used nanocomposites due to their high aspect ratio, higher contact area and their unique properties. These composites are used in a number of industrial applications, such as construction (building sections and structural panels), automotive (gas tanks, bumpers, interior and exterior panels), chemical processes (catalysts), pharmaceutical (as carriers of drugs and penetrants), aerospace (flame retardant panels and high performance components), food packaging and textiles, etc. Their interphase properties are essential for determining their proper design and safety application when applying large mechanical loads on them. In this work, a parametric analysis is performed to investigate how the change in the interphase properties influences the interphase shear stress (ISS) and interphase peel stress (IPS) in a nanoclay/polymer nanocomposite structure, subjected to axial load. The two-dimensional (2D) stress-function method is applied, which results in obtaining an analytical solution for ISS and IPS. The implemented parametric analysis shows how varying of the interphase mechanical properties (Young's modulus and Poisson's ratio) and their geometric properties (thickness and length) influence the value of the model interphase stresses. It was found, that increasing the value of Young modulus of the interphase does not change significantly the value of the model ISS, as well as the value of IPS, in the considered nanoclay/polymer structure. On the other hand, increasing the value of the interphase layer thickness becomes important for the value of ISS and IPS after 25nm. It turned out, that the interphase layer length is the most appreciable parameter, influencing both the model ISS and IPS. The obtained results could be useful for the proper design and safety application of similar nanoclay/polymer composites in industry.

Two-layer Factory-Made Exterior Panel for Low-Rise Housing Construction

Two-layer Factory-Made Exterior Panel for Low-Rise Housing Construction

Methodology to estimate logistics costs for vertically transported prefabricated wall panels

Abstract When transporting prefabricated exterior panels vertically, shipping frame types and site conditions affect panel logistics. Thus, it is crucial that project participants estimate the logistics costs considering these factors, which vary by projects, to select the most economic option rapidly and consistently for a specific project in addition to three important objectives of panel logistics (i.e. number of trailers, reshuffling effort, and panel stability). In this study, the authors developed a methodology to generate loading plans for different types of shipping frames and site conditions using both first fit and next fit algorithms and evaluate the cost-related items for the loading plans considering project conditions. To demonstrate the usefulness of the methodology, the authors conducted a case study and compared the logistics costs for three different frame options considering site conditions. The results show that the methodology enables project participants to identify the advantages and disadvantages of different frame options based on given site conditions, which can guide project participants to make informed decisions about the preferred frame option.

Structural evaluation of unitized curtain wall systems by using inter-story drift test

A curtain wall enhances the aesthetic appeal of a building and protects it from harmful environmental conditions. As one of the most significant façade curtain walls, Unitized Curtain Wall Systems (UCWS) are constructed concurrently with the construction of the structural framing system. Because of their lightness, ease of application, functionality, and various design possibilities, UCWSs are frequently used as exterior panels on high-rise buildings. UCWSs must be designed to resist external loads such as wind and seismic load during their lifetime. A structural performance evaluation of the UCWSs is therefore one of the most important criteria for their design. American Architectural Manufacturers Association (AAMA) suggests conducting a full-scale test on a mock-up to determine the structural performance in accordance with AAMA 501.4. In this study, an inter-story drift test was performed according to the AAMA 501.4 standard on a two-story UCWS system, comprised of six panels 1430.8 mm wide and 4215 mm high. The structural behavior of the system was assessed using horizontal and vertical displacement meters that were placed at various points in the system. In addition, a simplified numerical model of the system was prepared and experimental studies were supported by finite element analysis.

Total Heavy Prefabrication: Santo António dos Cavaleiros (SAC) and Quinta do Morgado (QM). Overview of the building process, exterior panel pathologies and a study for their rehabilitation

Total Heavy Prefabrication: Santo António dos Cavaleiros (SAC) and Quinta do Morgado (QM). Overview of the building process, exterior panel pathologies and a study for their rehabilitation

Performance of roof‐cool paints prepared using organic acrylic polymer binder and inorganic additives for the thermal reduction in buildings

AbstractThe passive cooling strategy has gained significant attention in recent years due to the dreadful impact of active cooling on energy demand and global warming. This work reports on preparing water‐based new roof‐cool paints and studying their utility on thermal and reflectivity performance. The acrylic binder was synthesized via free‐radical water‐based emulsion polymerization using vinyl acrylic monomers ‐three new paint formulations prepared using the as‐prepared acrylic polymer binder with inorganic pigments. To study the roof‐cooling performance of the prepared paints, a cubical plywood‐box model fitted with the painted cement panel was considered the roof with a halogen lamp to simulate the sunlight. The digital thermal sensors are used to record the temperature at the exterior panel surface, interior panel surface, and model box center point to record temperature with time. The study revealed that the prepared roof‐cool paints showed a synergistic effect in reflecting the incident light and heat rejection with peak temperature reduction in the internal air reaching up to 2.8° C inside the model. These type roof‐cool paint coatings on a roof‐top could undoubtedly bring the temperature down inside the building and achieve substantial savings from the energy utilized for cooling comfort.

Auralization of electric vehicle's interior noise SEA simulation

Statistical Energy Analysis (SEA) has become an essential step to minimize the vehicle interior noise level. The outcome of SEA is typically 1/3 octave spectrum, and consequently it is difficult to understand the subjective effect of interior noise. This study investigated two approaches to achieve the binaural synthesis of SEA results. One is directly from the SEA 1/3 octave result and the measured coherence function. The other makes use of Source Path Contribution (SPC) to estimate the time signals on the exterior panels and subsequently applies the SEA results as a set of Finite Impulse Response (FIR) functions. Both approaches seem to result in realistic binaural signals as well as the correctly scaled sound pressure levels at the receivers. The one using SPC results can generate the input data for an NVH driving simulator by decomposing the harmonics and the masking noises. This means that the SEA result can be experienced by driving the simulated vehicle freely.

Study on secondary deepening design of exterior wall panel of Substation Prefabricated Building

With the continuous progress of the manufacturing industry and the urgent demand for new building forms in the electric power industry, the prefabricated steel structure buildings have been widely applied in the substation design of State Grid Corporation of China, which can effectively reduce the wet operation on site and the project cost. This paper takes the exterior panel design of prefabricated steel structure building in substation as the research object, and explores the technical application of the secondary design of exterior panel of prefabricated steel structure building through combining the actual project and the existing wall panel type, which provides a reference for the development direction of prefabricated building in the future.

A feasibility study to determine the use of baited pots in Greenland halibut (Reinhardtius hippoglossoides) fisheries, supported by the use of underwater video observations

High incidental catches of Greenland shark (Somniosus microcephalus) in Nunavut’s Greenland halibut (Reinhardtius hippoglossoides) fishery has led to studies on the feasibility of capturing Greenland halibut with baited pots. In this study, catch rates among six experimental pots are compared. In addition to this, underwater video observations of Greenland halibut interacting with two of these experimental pot types are quantified in order to help provide recommendations on future pot designs. Catch rates of Greenland halibut differed among pots with different entrance mesh types, and none of the pots produced substantial amounts of bycatch. Strings of pots were deployed within a narrow corridor between baited gillnets targeting Greenland halibut, which may have affected catch results. Video observations revealed Greenland halibut entangled by their teeth significantly more often in entrance funnels constructed with 50 mm than with 19 mm clear monofilament netting and the entrance rate was 45% higher with the 19 mm netting. Greenland halibut that successfully entered a pot repeatedly became entangled by their teeth in 58 mm netting used in the side and end panels and in a horizontal panel used to separate the pot into a lower and upper chamber. The majority (80%) of Greenland halibut were observed to approach a pot against the current. The downstream entrance was aligned with the current in 52% of the observed Greenland halibut approaches. Seventy percent of entry attempts and 67% of successful entries occurred when fish approached against the current and when the entrance was aligned with the current. These observations lead to recommendations that future studies consider developing a four entrance pot to ensure an entrance is always aligned with bottom currents. Based on these observations of entanglements, it is recommended to use 19 mm clear monofilament netting in the entrance funnel, 100 mm polyethylene netting in the exterior panels, and 19 mm polypropylene netting in the horizontal panel when targeting Greenland halibut. Three Greenland sharks were observed interacting with the pots in the video sets, but none were captured or damaged the pots during the potting experiments, providing validity to the use of pots to mitigate the capture of Greenland shark in Nunavut territorial waters.

Иркутская «боль»: 1-335 серия – сейсмоопасное жилье, снос или реконструкция. Поиск возмож-ных решений на примере района Ново-Ленино в Иркутске

The paper examines a scenario for developing the housing sector using the Integrated Area Develop-ment Standard on the example of the Novo-Lenino district in Irkutsk. Most of the housing stock in the area comprises prefabricated housing of 1-335 series in critical condition and potentially life threaten-ing. When applying an empiric method, the objectives were identified, and solutions were found that allow a strategy and methodology for managing a massive housing area to be developed. At first sight, the 1-335 series residential buildings look like ordinary prefabricated housing that has lasted for 50 years and will serve as much again. However, apart from the obsolescence, in half a century, the build-ings have accumulated technical problems with load-bearing structures, facades (destruction of exteri-or panels because of atmospheric action) and civil engineering infrastructure. However, the most criti-cal situation has arisen because these buildings do not meet the current requirements for seismic re-sistance; for Irkutsk, this factor amounts to 7–9 points. A number of problems related to the continued operation of such housing have arisen, which need to be addressed. One solution to this situation is a strategy for regenerating the housing sector. Replacing seismically unsuitable residential buildings with new housing estate will help create a comfortable space for living with modern architectural concepts. Legal arrangements need to be developed to ensure the feasibility of regeneration projects.

Nonlinear Panel Flutter Analysis at High Supersonic Speed (Dept.M)

Exterior panels forming the exterior skin of flight vehicles traveling through the atmosphere at high supersonic speeds are often susceptible to the occurrence of limit-cycle type self-excited vibrations called flutter. Panel flutter is resulting from the dynamic instability of the aerodynamic, inertia, and elastic forces of the system. The equations of motion for panel flutter are derived using Von Karman's large deflection plate theory and quasi-steady aerodynamic theory. The equations are given in terms of the displacement and are presented in non-dimensional form. Galerkins method is used to transform the system of nonlinear partial differential equations into a system of nonlinear ordinary differential equations in time variables. The obtained equations are then solved by the method of harmonic balance and Newton-Raplison algorithm. The results are compared with both theoretical and experimental results given in publications. Then, a parametric study is performed to study the effects of aerodynamic loading, aerodynamic damping, structural damping, in-plane applied loads, thermal stresses and cavity pressure.

Damping Material for Stabilization of Panel Flutter at High Supersonic Speed

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