Parametric study of expanded metal shading toward Daylight Glare Possibility (DGP) optimization

Patented in the 1880s and having a longstanding industrial history, expanded metal sheet has a remarkable reputation for its application. However, despite the benefits of its use and numerous studies has been conducted on window shading and its daylight evaluation, research on extended metal shading’s daylight performance is still limited. This paper investigates the role of expanded metal shading to assess Daylight Glare Possibility (DGP) in Shimonoseki, Yamaguchi, Japan, utilizing parametric design approach and Multi-Objective Optimization (MOO). The simulation and analysis were undertaken to determine how expanded metal can optimize DGP, the significance of improvement, the relationship between the View (aperture) and the DGP, and which parameters have the most influence in driving the aperture size and the DGP value. Analyzing 2322 solutions and 88 Pareto frontiers resulted from the MOO, several findings has been portrayed. Firstly, the shading View (aperture) shows a significant positive correlation to the DGP. Secondly, parameter Strand/W was identified as the most influential parameter that drive the objectives. Thirdly, the validation process portrays optimization in DGP by 38%. The results of the proposed methodology are expected to become an immediate geometry and performance feedback for designers and industries, supporting design decision-making processes during early design phase.

Development of Folded Expanded Metal Mesh with Sound Absorption Performance

Reverberation time (RT) is an important factor affecting the quality of indoor acoustics. Using sound-absorbing materials is one method for quickly and effectively controlling RT, and installation in the ceiling is a common location. Sound-absorbing ceilings come in many forms, with light steel joist ceilings commonly used in office spaces, classrooms, and discussion rooms. Light steel joist ceilings are often matched with sound-absorbing materials such as gypsum board, mineral fiberboard, rock wool, and coated glass wool, but such materials may have durability and exfoliation problems. Therefore, considering performance and health, in this research, we aimed to design an expanded metal mesh (EMM) structure specimen for sound-absorption material, namely folded expanded metal mesh (FEMM). The results show that the FEMM can significantly improve the sound-absorption performance of the expanded metal mesh. Theof single panel is 0.05–0.35, and theof FEMM is 0.65–0.85. On the other hand, the sound-absorption performance of the full frequency band has been significantly improved. Furthermore, the field validation result shows that RT decreased from 1.05–0.56 s at 500 Hz, meanwhile, the sound pressure level (SPL) is still evenly distributed, and speech clarity (C50) is increased by 5.6–6.5.

Experimental Study of Explosion Mitigation by Deployed Metal Combined with Water Curtain

In this paper, protective barriers made of perforated plates with or without a water cover were investigated. In urban areas, such barriers could be envisaged for the protection of facades. An explosive-driven shock tube, combined with a retroreflective shadowgraph technique, was used to visualize the interaction of a blast wave profile with one or two plates made of expanded metal. Free-field air blast experiments were performed in order to evaluate the solution under real conditions. Configurations with either one or two grids were investigated. The transmitted pressure was measured on a wall placed behind the plate(s). It was observed that the overpressure and the impulse downstream of the plate(s) were reduced and that the mitigation performance increased with the number of plates. Adding a water layer on one grid contributed to enhance its mitigation capacity. In the setup with two plates, the addition of a water cover on the first grid induced only a modest improvement. This blast mitigation solution seems interesting for protection purposes.