Bolts cannot be loaded axially according to real field conditions in assembly lines. The main reasons for this are that the loads cannot be applied centred due to the plate thickness and the holes are wider than the bolt. This creates a change in the...

This study addresses a gap in the literature by simultaneously optimizing noise reduction and structural integrity in silencer design. A novel silencer model offering advantages over conventional designs was developed. In the first phase, the initial optimization model was developed to minimize noise levels while considering environmental constraints. CFD analyses using NEC Acostix and Ex-Tuner calculated noise, temperature, and pressure, followed by validation in SimScale. The results demonstrated improved efficiency in reducing pressure loss and noise. A silencer with Ø 800 mm diameter, 3000 mm length, and Ø 355.6 mm exhaust connection was manufactured and tested, achieving 96 dB(A) at 1 m, with front and side measurements of 85.1 dB(A) and 74.4 dB(A), respectively. In the second phase, fastener durability in silencer support plates was optimized using tensile tests and FEA in Ansys R19.2. Parametric analyses for M4-M20 bolts were conducted, and regression analysis in Minitab (Minitab Statistical Software Version 21.1) showed 97.74% accuracy. An objective function was developed using curve fitting. The second optimization problem, incorporating design constraints, was solved using the interior-point and Lagrange multipliers methods. This study provides a foundation for silencer design, ensuring both structural reliability and noise control. Future research will explore performance eco-friendly solutions across varying generator power levels.

Bu makale, değiştirilmiş karınca kolonisi optimizasyonu (DEKKO) algoritmasının redüktör mühendislik probleminin çözümüne yeniden odaklanılmasına dayanmaktadır. DEKKO, Karınca Kolonisi Algoritmasının (KKO) avantajlı özelliklerinin birleştirilmesiyle oluşturulmuştur.DEKKO ile KKO ’da değişiklik yapılarak daha önceden literatürde farklı tekniklerle yapılan çalışmalardan daha iyi sonuçların elde edilmesi amaçlanmıştır. Algoritma, en etkili sonuç elde edilene kadar 20 kez çalıştırılmıştır. İterasyon sayısı 14 olmak üzere en iyi performans sonucu olarak 3105,8779 sonucu elde edilmiştir. Bu işlem, algoritmada 100 adet karınca kullanılarak 66,81saniyede tamamlanmıştır. Literatürdeki sonuçlarla karşılaştırıldığında DEKKO, literatür sonuçları arasında olduğu ve başarılı bir çözümle sonuçlandığı gözlemlenmiştir. Kullanıcılar, DEKKO algoritmasını kullanarak simülasyon yoluyla redüktör tasarımı ve ön üretim hakkında kolaylıkla bilgi edinebilmektedir. Böylelikle maliyet ve zaman tasarrufun açısından kullanıcılara katkıda bulunulması amaçlanmıştır.

Considering the presence of airborne viruses, there is a need for renovation in refuse chutes, regarded as the first step in recycling household waste in buildings. This study aimed to revise the design of existing refuse chutes in light of the challenging experiences in waste management and public health during the coronavirus pandemic. This research primarily focused on the risks posed by various types of coronaviruses, such as the novel coronavirus (COVID-19) and acute respiratory syndrome (SARS and SARS-CoV), on stainless steel surfaces, with evidence of their survival under certain conditions. Refuse chutes are manufactured from stainless steel to resist the corrosive effects of waste. In examining the existing studies, it was observed that Casanova et al. and Chowdhury et al. found that the survival time of coronaviruses on stainless steel surfaces decreases as the temperature increases. Based on these studies, mechanical revisions have been made to the sanitation system of the refuse chute, thus increasing the washing water temperature. Additionally, through mechanical improvements, an automatic solution spray entry is provided before the intake doors are opened. Furthermore, to understand airflow and clarify flow parameters related to airborne infection transmission on residential floors in buildings equipped with refuse chutes, a computational fluid dynamics (CFD) analysis was conducted using a sample three-story refuse chute system. Based on the simulation results, a fan motor was integrated into the system to prevent pathogens from affecting users on other floors through airflow. Thus, airborne pathogens were periodically expelled into the atmosphere via a fan shortly before the intake doors were opened, supported by a PLC unit. Additionally, the intake doors were electronically interlocked, ensuring that all other intake doors remained locked while any single door was in use, thereby ensuring user safety. In a sample refuse chute, numerical calculations were performed to evaluate parameters such as the static suitability of the chute body thickness, static compliance of the chute support dimensions, chute diameter, chute thickness, fan airflow rate, ventilation duct diameter, minimum rock wool thickness for human contact safety, and the required number of spare containers. Additionally, a MATLAB code was developed to facilitate these numerical calculations, with values optimized using the Fmincon function. This allowed for the easy calculation of outputs for the new refuse chute systems and enabled the conversion of existing systems, evaluating compatibility with the new design for cost-effective upgrades. This refuse chute design aims to serve as a resource for readers in case of infection risks and contribute to the literature. The new refuse chute design supports the global circular economy (CE) model by enabling waste disinfection under pandemic conditions and ensuring cleaner source separation and collection for recycling. Due to its adaptability to different pandemic conditions including pathogens beyond coronavirus and potential new virus strains, the designed system is intended to contribute to the global health framework. In addition to the health measures described, this study calls for future research on how evolving global health conditions might impact refuse chute design.

In this study, a software has been developed for calculating static strength of bolted steel plates. This software has been developed by adding equations covering the bending moment that occurs during a tensile test as well as under real loading conditions. In order to test the accuracy of this...