Detection of weak joints and damages for beams using machine learning

For maintaining the safe operation of structures, it is necessary to develop SHM methods that can detect not only the presence of cracks in the structure but also any alterations of its fastening conditions. The current paper presents a method for developing an Artificial Intelligent model that can detect if a beam is affected by transverse cracks and at the same time, by improper boundary conditions. To this aim, a cantilever steel beam is considered as the in the current study. The training data for the artificial neural network (ANN) is created using an original analytic method which allows calculating the natural frequency loss caused by the occurrence of transverse cracks even if the beam is improperly fastened. The intelligent model is trained by employing the MATLAB software and tested using data acquired from numerical simulations. The results show very high accuracy in determining the presence of transverse cracks, and the capability of detecting the presence and severity of improper clamping conditions

Public acceptance of CCS/CCUS technology in onshore areas in NW Poland

The research is a part of the AGaStor project realized in AGH-UST and University of Stavanger. The aim of the paper is to present social aspects of the developing the CCS/US technology in Poland described as social awareness (SA) and public acceptance (PA). The main research questions of the CCS/US PA concentrates on knowledge, acceptance of the technology, risks and benefits, the existence of NIMBY movements [1]. The quantitative method of analysis of CCS PA is a survey method. The most of the former research was realized only in small communities [2, 3]. The AGaStor research describes the mezzo-social level of the CCS/US PA. The randomized sample (N= 695) was made in Zachodniopomorskie region (West-North Poland) in 2021. It allows to recognize differences of the level of CCS/US PA in different in that part of Poland. The main variables which influence CCS/US PA are: place of living, education, economic situations and general worldview of the respondents. The results show the correlation between place of living and CCS PA (higher PA in big cities); education with CCS SA (higher declarations of knowledge and SA by well educated people); NIMBY potential in villages and small towns, and the pro-technological worldview with the CCS PA. The research points that the main social obstacle is the lack of knowledge about the CCS/US technology. Even respondents who declare the general acceptation of new technologies in energy production are ambivalent towards acceptance of CCS/US

Techno-economic modelling of the Baltic CCUS onshore scenario

Techno-economic modelling of the Baltic onshore CO2 transport, storage, and utilization scenario included HeidelberCement-owned Kunda Nordic Cement (KNC) plant, the main Estonian cement producer, four Estonian and one Latvian power plant and CO2 mineral carbonation of the oil shale ash, as possible CO2 use option. In 2019 nearly 6.5 Mt of oil shale ash (OSA) was produced in Estonia from energy production. Estonian OSA could be used as an effective sorbent in the proposed CO2-mineralization process, using CO2 from flue gas and producing precipitated CaCO3 (PCC) of high quality. Mineral carbonation of 0.42 Mt CO2 using 3.8 Mt of fresh OSA and about 6.33 Mt CO2 produced annually by five Estonian and one Latvian plant transported by pipeline for storage into the North-Blidene structure in western Latvia are combined in the CCUS scenario. Cambrian Deimena Formation reservoir sandstone is located at the depth of 1035-1150 m in the selected saline aquifer. The average optimistic storage capacity of about 270 Mt allows planning CCUS project for 30 years. The share of the Estonian emissions avoided and stored in Latvia is 86.5 %, including 8.2 % by KNC, while Latvian stored emissions will compose 13.5 %. Annually 6.8 Mt CO2 could be captured, transported and injected, including 6 Mt CO2 avoided using transport and storage and 0.42 Mt CO2 avoided using MC of Estonian OSA. During 30 years nearly 204 Mt CO2 will be captured, used and stored, while 193 Mt CO2 could be avoided. The total average transport and storage (T&S) cost of the scenario is 18.4 €/t CO2 injected. This cost depends on the transport distance, according to the applied methodology, and it is the most expensive for the Eesti Energia PPs. The lowest T&S cost of 5.54 €/t CO2 injected will have Latvenergo TEC-2 PP located at a smaller distance from the storage site. At the price of EEAP (CO2 Emission Allowance Price in EU ETS) of 40 €/t CO2 and 50 €/t PCC, the CCUS scenario could be beneficial for three Eesti Energia and Latvenergo TEC-2 power plants. For the KNC and VKG Energia plants without CO2 use options, the higher EEAP of about 48-50 €/t CO2 is needed to cover all CCUS costs including capture, compression, transport, storage and monitoring. The transport and storage costs are distance-dependent, as pipelines are the most expensive part of the transport, storage and monitoring costs. At the present EEAP of about 90 €/t CO2, all the participating plants will get benefits from the proposed scenario. This study is supported by CLEANKER project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement n. 764816

Structure and movement, let’s not kill Chronos

The myth of Chronos that devours his children is the allegorical expression of time that ends everything, but there is another reading: that time exists and allows us to understand the idea of a process, of evolution, both biologically and in any other aspect of life. The structure is the static, current, measurable morphological expression of everything that has a physical manifestation. Movement is the expression of life that is inexorably written on the structure and is responsible for its dynamism and change. We have developed the ability to analyse the structure in a systematic and detailed way, isolating it from time, and therefore depriving it of the movement that animates it, fixing the moment with static photographic images. With direct cephalometric techniques or on radiography we have defined points and reference systems, measured, compared, made proportions, and described the layout. Like the Art, the Morphological Sciences evolve from a two-dimensional vision to a three-dimensional one and we have given importance to empty spaces. But unlike art, we have difficulty internalizing and becoming aware of movement and the vital energy that animates it. Studying Movement means studying Form along Time. Structure and Function are two sides of the same coin, and our field is a clear example of this. We cannot work on occlusion without understanding the functions associated with the whole system: breathing, swallowing, chewing, are the main sources of stimuli responsible for the development of the Stomatognathic System, which has the movement as its main engine. In our clinical practice we are convinced that seeking an integration between Form and Function provides balance and health to the system and therefore delays the negative effects of Time, and coherently understanding the Form-Function-Time triad provides a broader understanding of development and balance of our system

Skull base flexion and its influence on chewing

Skull base asymmetries can occur in the intrauterine period, manifesting from birth as craniofacial asymmetries and should be investigated both in the maxilla and mandible and in the craniofacial region, as they are related to the base of the skull. The objective of this study was to explain that treatment using Craniofacial Biodynamics (CFBD) enables symmetrical craniofacial growth, being recommended from three to six years of age, when the processes of skull base remodeling cease. This study was based on exploratory bibliographic research, aiming at a better understanding of the concepts presented in this therapeutic approach, to verify the influence that such concepts exert on treatment through CFBD. It was evidenced in this research that these asymmetries may be corrected, or even minimized through the CFBD, which relates the ontogenetic development of the skull base with orofacial development

Unsteady state heat transfer analysis of a convective-radiative rectangular fin using Laplace Transform-Galerkin weighted residual method

The present investigation is concerned with the development of non-power series solutions for the unsteady state nonlinear thermal model of a radiative-convective fin having temperature-variant thermal conductivity using Laplace transform-Galerkin weighted residual method. In the study, it is demonstrated that the symbolic solutions do not involve a large number of terms, complex mathematical analysis, high computational cost, and time as compared to the power series solutions in previous studies. The solutions allow effective predictions of the extended surface thermal performance over a large domain and time. The results of the non-power series solutions are verified numerically, and very good agreements are established. Parametric studies are carried out with the aid of the symbolic non-power solutions. It is found that as the conductive-convective and conductive-radiative increase, temperature distribution decreases since the rate of heat transfer becomes augmented and hence, the fin thermal efficiency is improved. Additionally, when the thermal conductivity of the fin increases, the temperature distribution in the passive device increases. The temperature increases with time at the different positions in the fin. Following the time histories of the solution, it is shown that unsteady state solutions converge to a steady state as time progresses. It could therefore be stated the developed non-power series analytical solutions provide a good platform for comparison of the nonlinear thermal analyses of fins in thermal systems

Research on dynamic stability of large deformation roadway with application of segmented resistance anchor bolt

The dynamic stability of large deformation roadway can be significantly affected by seismic vibration. In order to improve the support effect, a segmented constant resistance anchor bolt structure is proposed. The preload can be set in segments to effectively reduce the tension deviation. The support stability of this type of bolt is verified by field test and experimental simulation. Based on the bearing and deformation characteristics of surrounding rock, the supporting and installation, grouting process and anchor cable stress monitoring of this type anchor bolt are designed. Through the field measurement of the roadway, the variation laws of the rock swelling coefficient, anchor cable tension and roof subsidence under the condition of bolt support are obtained. A tunnel dynamic deformation test-bed is built to study the dynamic vibration response of the designed anchor bolt to alternating load. Applying orthogonal exciting force, the tension changes in different constant resistance sections are obtained. The results show that this type of bolt has remarkable effect of resisting alternating load, and the maximum tension deviation within ±200 m working face is less than 8 %, which has better support stability than conventional bolt

Research on reducing CWS value based on product lean design

The research on improving production efficiency and reducing labor cost by reducing production CWS is the focus of notebook computer manufacturing enterprises. This research breaks the traditional method of reducing CWS at the production end and chooses to find breakthroughs from the whole life cycle of products. Finally, innovatively based on product lean design, and from the product design side, explore the optimization opportunity to reduce the CWS value of product production, so as to achieve the purpose of reducing CWS. Firstly, laptop model S is selected as the research object, and its structure disassembly and analysis, assembly action research and station sequencing were carried out to preliminarily determine the product production process. According to the production bottleneck process time, the current CT of the production line was determined to be 13S, and the initial CWS value of the production line was calculated to be 0.2167. Then, based on the principles of lean product design, the CONN of FAN, Battery, Speaker and RCT are optimized to make their assembly easier. The SSD fixation method, I/O BKT and I/O modular design are optimized to eliminate the need for auxiliary BKT assembly. In addition, Center Hook and WLAN were integrated on MB, and their assembly was cancelled, so that the design of the optimized parts was more integrated and modular. Then, the optimized product was rearranged for production. The CWS value of the optimized product was 0.1589, which decreased by 27 % compared with that before optimization

Modeling of the influence of the wear of the cutting wedge of the tool on the stability of the metal turning process

metalworking today, the assessment of the degree of wear of the cutting wedge of the tool during its operation is an extremely relevant and in-demand task. Even though a large number of methods for monitoring tool life have been developed, there are no unambiguous mathematical dependencies that determine the degree of wear of the cutting wedge according to indirectly measured data. The article proposes a new mathematical apparatus that has not been used before, which makes it possible to adequately interpolate vibrations and temperature in the contact zone into tool wear. The study aim of the study is to develop a method for indirectly estimating the wear rate of the tool, based on a consistent model of intersystem communication describing the force, thermal, and vibration reactions of the cutting process to the shaping movements of the tool. The study consists of experiments on a measuring stand and numerical modeling of the obtained data in Matlab with a comparative evaluation of them with the results of modeling of the mathematical apparatus proposed in the article. The results show that the mathematical model proposed in the article is applicable for an adequate interpretation of experimental data

Effect of reducing the vibration of a frame-spacing arrangement

The methods of arranging frame spacing are explored for reducing the vibration of a cylindrical shell. According to the principle that an aperiodic structures will produce irregular reflections on structural waves, resulting in structural vibration attenuation, two methods of arranging frame spacing are adopted: periodic frame spacing and random frame spacing. Using the two methods, the frames of cylindrical shell models are arranged, and then, using the finite element method (FEM), the vibration response of the cylindrical shells is calculated and compared. It can be found that, for the finite-length cylindrical shells, the aperiodic arrangement of the frame spacing can decrease the vibration level of the cylindrical shells in some specific high-frequency band. For example, for the cylindrical shells with a diameter of 7.6 m and a length of 8.4 m, the frame-spacing arrangement is random, and the vibration level is reduced in about 350-600 Hz, with a maximum reduction of up to 9 dB