Explore the vast range of titles available.

This work examines the thermal response of symmetric sandwich beams composed of a three-layer (0°/core/0°) configuration under localized thermal actions in the form of a thermal point load, thermal line load and thermal patch load. In the present work, the term “quasi-3D” refers to higher-order beam models in which the transverse strain (εz ≠ 0) is included within a one-dimensional beam formulation through an enriched displacement field. The formulation captures transverse normal deformation and improved through-thickness stress variation, while retaining the computational simplicity of beam theory and not representing a complete three-dimensional thermoelastic analysis. The influence of transverse normal strain (εz ≠ 0) is incorporated in the displacement field of trigonometric shear deformation theory (TSDT) and parabolic shear deformation theory (PSDT) to enhance accuracy. The novelty of this work lies in the application of these quasi-3D theories to sandwich beams under localized thermal point, line and patch loads, which has received limited attention in earlier research work. Thermal deformations and stresses corresponding to different aspect ratios are analyzed using the principle of virtual work in conjunction with Navier’s method. A script with the help of MATLAB software has been developed to generate the output efficiently across a range of aspect ratios. The results reveal that TSDT consistently predicts higher stress magnitudes and displacements under thermal loads. It is also noted that Timoshenko beam theory (also known as first-order shear deformation theory (FSDT)) offers computational efficiency with acceptable accuracy for higher values of aspect ratios. The convergence of results at high values of aspect ratio validates the applicability of simplified refined models. This comparative framework provides practical insights for selecting appropriate theories in thermal design of composite sandwich structures.

The production of non-centrifuged cane sugar in Colombia takes place in post-harvest facilities that generate significant heat and steam resulting from the evaporation of cane juices during the process. This study aimed to improve the comfort conditions of a facility of this type in the municipality of Pacho, Cundinamarca, Colombia, through bioclimatic simulation, where the enclosure on the walls and the lantern window were modified. The evaluation of adaptative thermal comfort revealed that configurations with open perimeter and lantern window demonstrated the best bioclimatic behavior. This is attributed to the increased ventilation area and chimney effect, which optimizes the transfer of heat and mass. Likewise, it was observed that there is a generalized behavior of thermal discomfort for workers in the thermal zone of the oven, due to the high emissions of heat and steam in this specific area.

In this paper, we apply a digital holographic microscope (DHM) in conjunction with stroboscopic acquisition synchronization. Here, the temperature-dependent decrease of the first resonance frequency (S1(T)) and Young’s elastic modulus (E1(T)) of silicon micromechanical cantilever sensors (MCSs) are measured. To perform these measurements, the MCSs are uniformly heated from T0 = 298 K to T = 450 K while being externally actuated with a piezo-actuator in a certain frequency range close to their first resonance frequencies. At each temperature, the DHM records the time-sequence of the 3D topographies for the given frequency range. Such holographic data allow for the extracting of the out-of-plane vibrations at any relevant area of the MCSs. Next, the Bode and Nyquist diagrams are used to determine the resonant frequencies with a precision of 0.1 Hz. Our results show that the decrease of resonance frequency is a direct consequence of the reduction of the silicon elastic modulus upon heating. The measured temperature dependence of the Young’s modulus is in very good accordance with the previously-reported values, validating the reliability and applicability of this method for micromechanical sensing applications.

When it comes to guaranteeing appropriate performance for buildings in terms of energy efficiency, the building envelope is a crucial component that must be presented. When a substance goes through a phase transition and either gives out or absorbs an amount of energy to provide useful heat or cooling, it is called a phase-change material, or PCM for short. Transitions often take place between the matter’s solid and liquid states. Buildings use PCMs for a variety of purposes, including thermal comfort, energy conservation, managing the temperature of building materials, reducing cooling/heating loads, efficiency, and thermal load shifting. Improved solutions are applied using new method and approach investigations. Undoubtedly, researching and applying PCM use in building applications can help create buildings that are more energy-efficient and environmentally friendly, while also increasing thermal comfort and consuming less energy. It provides a possible answer to the problems posed by climate change, rising energy demand in the built environment, and energy use optimisation. However, it is true that no particular research has yet been conducted to thoroughly analyse the linked PCM applications in the building industry. Thus, the principal tactics are addressed in this paper to determine current and efficient methods for employing PCMs in buildings to store thermal energy. By gathering around 50 instances from the open literature, this study conducts a thorough assessment of the up-to-date studies between 2016 and 2023 that used PCMs as thermal energy storage in building applications. As a result, this review aims to critically evaluate the PCM integration in buildings for thermal energy storage, identify a number of issues that require more research, and draw some important conclusions from the body of literature. Specifically, the building envelope roof and external wall uses of PCMs are highlighted in this research. Applications, general and desired characteristics, and PCM types and their thermal behaviour are described. In comparison to a traditional heat storage tank that simply contains water, this review indicates that a water storage tank containing 15% PCM improves heat storage by 70%. Also, less than 7 °C of internal air temperature was reduced by the PCMs in the walls, which avoided summer warming. Finally, using PCM for space cooling resulted in substantial energy savings across the various seasons.

Plasma-facing materials (PFMs) in fusion reactors are inevitably subjected to severe thermal shocks, making the performance of tungsten (W)-based PFMs under repetitive high thermal loads critical for the long-term stable operation of fusion reactors. Potassium-doped W (W–K) alloys present a promising alternative for PFMs due to their superior thermal and mechanical properties. However, unlike conventional second-phase particles, the K bubbles within W alloys do not form distinct phase interfaces with the W matrix, leaving their behavior poorly understood under transient thermal loads. This study investigates the effects of cyclic thermal loads on the evolution of K bubbles and mechanical properties of W–K alloys. Thermal load tests were conducted with a single-pulse duration of 1 s at absorbed power densities of 10, 13, 15 and 20 MW m−2 for 50 cycles at room temperature. Tensile test results indicate an unexpected increase in ductility in the W–K alloy while maintaining high strength after exposure to thermal loads at 10 and 13 MW m−2. Microstructural analyses reveal that K-tubes with large aspect ratios rupture due to Rayleigh instability, leading to the formation of well-dispersed, nano-sized polyhedral K bubbles. These fine K bubbles, with abundant dislocations at their interfaces, serve as dislocation sources, enhancing ductility. The present work offers a physical depiction of K bubble evolution in W–K alloys under thermal fatigue conditions relevant to fusion environments, suggesting a strategy for optimizing their mechanical properties by promoting the formation of nano-sized, interface-dislocation-decorated K bubbles.

The future perspective of using topology optimization to solve challenging design-dependent physics problems motivates the creation of methods with clear structural boundaries and well-defined volume. This paper develops the topology optimization of binary structures (TOBS) method to include design-dependent fluid pressure and constant thermal expansion loads. Topology design in thermoelastic and fluid pressure problems have been only handled separately up to date. To the authors’ best knowledge, this is the first work to consider both type of loads simultaneously within a structural topology optimization framework. The TOBS method uses discrete design variables, sensitivity filtering, and formal mathematical programming (integer linear optimization) to achieve convergent and mesh-independent solutions. The discrete nature of the method presents attractive features when dealing with design-dependent body and surface loads. In this paper, we use the structural mean compliance and volume as functions for optimization. The sensitivity analysis is carried out using the adjoint and semi-analytical methods. Numerous examples are shown to design novel structural designs which perform well under the applied fluid pressure and thermal loads. The observed computational times signify the practicability of integer programming for structural optimization problems.

A substantial share of the building sector in global energy demand has attracted scholars to focus on the energy efficiency of the building sector. The building’s energy consumption has been projected to increase due to mass urbanization, high living comfort standards, and, more importantly, climate change. While climate change has potential impacts on the rate of energy consumption in buildings, several studies have shown that these impacts differ from one region to another. In response, this paper aimed to investigate the impact of climate change on the heating and cooling energy demands of buildings as influential variables in building energy consumption in the city of Poznan, Poland. In this sense, through the statistical downscaling method and considering the most recent Typical Meteorological Year (2004–2018) as the baseline, the future weather data for 2050 and 2080 of the city of Poznan were produced according to the HadCM3 and A2 GHG scenario. These generated files were then used to simulate the energy demands in 16 building prototypes of the ASHRAE 90.1 standard. The results indicate an average increase in cooling load and a decrease in heating load at 135% and 40%, respectively, by 2080. Due to the higher share of heating load, the total thermal load of the buildings decreased within the study period. Therefore, while the total thermal load is currently under the decrease, to avoid its rise in the future, serious measures should be taken to control the increased cooling demand and, consequently, thermal load and GHG emissions.

Structural health monitoring (SHM) is essential for preserving historical and modern infrastructure by tracking dynamic properties such as frequencies and mode shapes. Changes in these properties can indicate structural damage, but environmental factors like temperature can also cause similar variations, complicating damage detection. This study investigates from an experimental point of view the effect of temperature on the dynamic behaviour of masonry structures, focusing on a masonry wall subjected to thermal load variations within operational conditions. The experimental setup involved a masonry wall specimen tested at the Structural Laboratory of the University of Minho, Portugal. The mock-up was subjected to various boundary conditions and loading scenarios. The results showed that the natural frequencies of the masonry wall can be significantly influenced by temperature changes, variations strictly related to the boundary conditions and the stress acting on the mock-up. In contrast, mode shapes seem not to be affected by temperature variations. This study provides valuable insights into the temperature-induced variations in the dynamic properties of masonry structures, emphasising the need to consider environmental effects in SHM applications. By filtering out these environmental influences, more accurate damage detection and proactive maintenance strategies can be developed, enhancing the safety and longevity of both historical and modern structures.

The basic principles for controlling the thermal and technological regimes of the glassmaking process in furnaces used for sheet-glass production by the float method are presented. Fuel delivery is redistributed above the melting zone in order to improve the operating efficiency of the glass furnace. The technical results of using an efficient distribution of the thermal loads over the burners in the furnace is lower energy consumption in the melting process and higher product quality. It is important to maintain the prescribed level of iron oxides in the glass and to monitor the oxidation-reduction potential during the glass melting process.

This paper presents a collaborative optimization design methodology aimed at improving heat dissipation efficiency through the modulation of microstructural variations. The approach addresses the thermal protection requirements of high-temperature components, such as ceramic matrix composite turbine blades, which are subjected to complex and elevated thermal loads. Through the integration of numerical simulation and experimental validation, a bidirectional mapping model linking carbon nanotube (CNT) content with the macroscopic anisotropic thermal conductivity of the material was developed. Furthermore, a thermal conduction analysis and optimization framework for Ceramic Matrix Composite (CMC) high-temperature components under non-uniform thermal loads was established. This study expands the adjustable range of the material’s thermal conductivity by allowing flexible modulation of carbon nanotube content. The results demonstrate that this methodology effectively enhances the heat dissipation capacity of CMC materials in extreme thermal environments: the maximum surface temperature of the optimized flat plate is reduced by 8.96%, the peak temperature gradient is lowered by 46.64%, and the maximum thermal stress is decreased by 38.17%. This research provides new insights into the comprehensive integration of thermal dissipation requirements for CMC hot components.