A Novel Optimised Inter-Locking Connection For Steel Modular Building Systems To Enable Re-Use

Hot-rolled steel Modular Building Systems (MBS) represent the highest level of Off-Site Con-struction (OSC) in which prefabricated, and often prefinished steel modules are delivered to site on a ‘just-in-time’ basis and assembled into complete building systems. Besides the already well-known advantages such as tight tolerance control, reduced on-site human intervention and speedier construction times, the context of the ongoing climate emergency has brought forward the connection between circular economy (CE) and opportunities of steel MBS for disassembly and reuse. However, the use of hybrid structural systems, the functionality of inter-modular connections, and the effects of complex and demanding load transfer paths often question the actual prospects of deconstruction, repair, relocation, or reuse. So far, inter-module connections have been heavily influenced by conventional design methods, relying on bolts, welds or even prestressing strands, which require laborious on-site tasks and simplifying design assumptions, often raising uncertainty about structural behaviour of modular buildings.In an attempt to mitigate limitations of existing systems, a new inter-module connection was envisaged, inspired from the inter-locking method of joining. At the forefront of the develop-ment process, topology optimisation (TO) was adopted in the conceptual design of the main component of the joint, assisting the morphogenesis process which provided the final configu-ration of the novel system. The structural performance of the newly proposed connection was assessed through a series of static monotonic and quasi-static cyclic FE analyses. Results re-vealed that in terms of load-bearing capacity, ductility and energy dissipation ability, the struc-tural behaviour of the new connection was comparable to that of other inter-module joints in literature, while managing to tackle their limitations by introducing both an easy-to-install and easy-to-disassemble configuration with promising opportunities for reuse, further demonstrat-ing that inter-locking joints could be worthy competitors for traditional means of attachment in the future of modular construction.

On elevating the reliability of the hygienic assessment of water quality of natural sources of drinking water supply

Introduction. As new toxic substances accumulate in water bodies, improving the reliability of the hygienic assessment of water quality is put forward in the first place. For the correct solution of this problem, it is relevant to use the direct comparison of deterministic quantities such as the maximum permissible concentration (MPC) of toxic pollutants with the result of its measurements (C) and methods of approach for evaluating the results of research. Material and methods. To improve the reliability of hygienic assessment of water quality in the proposed method tolerance control, envisaging the elucidation of the implementation type inequality and estimation of the probability of this event: where is the risk of false imprisonment. The number of concurrent measurements of water quality parameters guaranteeing an acceptable level of risk of error of research results is established by the authority of sanitary-epidemiological supervision, receiving a limited level of tolerable error taking into account the possibilities of metrological assurance of conformity assessment/quality of water and its normative level. Results. It is shown that in cases when the compliance of controlled safety indicators is evaluated, the values of which are limited on both sides, as is the case when studying the physiological usefulness of water, it is necessary to establish a two-way range of values of the permissible probability of violation of the specified requirements. Conclusion. First installed: the rule “if it is impossible to argue that controlled water quality indicators do not meet hygienic requirements. Thus requirements are met” is not equivalent to the law “if the indicators meet the requirements, then they can’t be inappropriate”, which more reliably indicates compliance with these requirements.

L1 Adaptive Loss Fault Tolerance Control of Unmanned Hypersonic Aircraft with Elasticity

This paper investigates the fault tolerance control of hypersonic aircrafts with L1 adaptive control method in the presence of loss of actuator effectiveness fault. The hypersonic model considers the uncertainties caused by the features of nonlinearities and couplings. Elasticity is taken into account in hypersonic vehicle modeling which makes the model more accurate. A velocity L1 adaptive controller and an altitude L1 adaptive controller are designed to control flexible hypersonic vehicle model with actuator loss fault. A PID controller is designed as well for comparison. Finally, the simulation results are used to analyze the effectiveness of the controller. Compared to the results of PID controller, L1 controllers have better performance.

Digital technologies for grain protection

A remote monitoring system has been created for the monitoring of the condition of the stored grain. It includes a set of grain mass measurements combined with a personal computer. The measurement provides prompt and tolerance control of the basic parameters of the grain mass condition – temperature, relative humidity and the presence of harmful insects and mites in the mode of on‑line and in dynamics.