Nonlinear seismic analysis procedures can accurately estimate structural responses but are computationally intensive, making them impractical for engineering design. This study provides the first comprehensive evaluation of N2 and modal pushover analysis for eccentrically braced frames (EBFs), revealing their strengths and limitations in predicting link rotations, shear demands, and drift distribution under Canadian seismic hazards. Analyzed were four-, eight-, and 14-storey chevron EBFs under real and artificial ground motions compatible with the response spectrum of Vancouver, Canada. The findings indicate that inelastic link rotations for all EBFs remain below the design limit of 0.08 rad, except for the upper two floors of the 14-storey EBFs. Seismic analysis reveals that maximum inelastic link shear forces often exceed design recommendations. It is also observed that both the N2 method and MPA procedure could reasonably predict the peak roof displacements for low-rise EBF buildings. In addition, while the MPA procedure provides better predictions of maximum inter-storey drifts over all storeys for medium-to-taller EBFs, inter-storey drifts are not predicted well in the N2 method. Additionally, the current code formula for estimating the fundamental period of EBFs predicts shorter periods than those obtained from analysis. An improved formula for estimating EBF periods is proposed.
Arkadiusz Gola, Chandima Ratnayake, Martin Krajčovič
Although the issues of design, organization, and management of industrial systems have been known in the literature for many years, the beginning of the 21st century, as a consequence of market changes and unprecedented technological development, initiated a change in the paradigms of organization and the need to use innovative tools for improving and optimizing production processes [...]
This chapter presents the activity conducted by the ITPA topical group (TG) on Diagnostics over about the last 15 years. Following a general introduction of the ITER Diagnostics led by their measurement roles, the document is organized in several subchapters detailing the design support, research and development activity conducted by each of the specialist working groups (WGs) of the TG. Please note that the magnetic diagnostics were supported at the TG without a specific WG. Their status is included in the general introduction. In the following some highlights of the subchapter’s contents are provided. Recent advances in ITER first wall (FW) diagnostics for the measurements of plasma-metallic wall interaction in support of the ITER research plan are reported. An InfraRed imaging Video Bolometer for ITER has been developed and tested on several tokamaks to measure the radiated power loss. A laser-induced breakdown spectroscopy (LIBS) technique which utilizes a pulsed laser beam to ablate locally by forming a crater, will measure local tritium inventory in the FW material. Real-time Residual Gas Analyzers will measure the neutral gas composition in a divertor port and an equatorial port during plasma operation. Due to the full metallic FW environment, the plasma-wall interaction in ITER will face several challenges such as the compromised radiated power and divertor heat flux measurements by reflection. Ray tracing and analysis codes have been developed to eliminate and correct the effects of reflection in the measurements. The characteristics of the reflecting surfaces depending on the roughness and angle of the incidence have been measured by dedicated experiments, and the results were applied to the reflection elimination. For the measurement of the metallic impurity radiation induced by eroded metallic atoms, a vacuum ultraviolet spectrometer has been developed and tested. An extensive thermonuclear diagnostic suite will be required to support the operation of ITER and the planned experimental program for future burning plasma experiments. Due to the harsh environmental conditions, the implementation of diagnostic systems in ITER is a major challenge. These conditions include high levels of neutron and gamma fluxes, neutron heating, particle bombardment. Therefore, the selection and design of diagnostic systems must take into account a number of phenomena previously unseen in diagnostic design. For this reason, the measurement of neutrons and confined or lost fast ions, with particular emphasis on alpha particles, is critical to ITER. The diagnostics associated with these measurements will be important for future plasma-burning experiments at ITER. The high neutron emission and very large plasma size in ITER make neutron diagnostics the main diagnostic method used to measure plasma parameters such as fusion power, fusion power density, ion temperature, energy of fast ions and their spatial distributions in the plasma core. Active spectroscopy techniques are methods where a neutral particle beam is injected into the plasma and information on plasma parameters is extracted from the measurement of line emission resulting from the beam-plasma interaction, either by plasma ions or by beam atoms. Spatial localization is achieved by crossing the beamline and multiple observation lines. The ITER plasma will be a high temperature, moderately dense, fully ionized collisional plasma. The plasma facing surfaces are principally metallic being fashioned from beryllium or tungsten but many other elements, arising from either structural or from operational needs, may enter this plasma. The energy range of the emitted photons range from meV (infra-red) to multi keV (x-rays) and originate from all areas of the plasma volume. The primary role of passive emission diagnostics is to identify what is in the plasma from spectral signatures. Extracting quantitative information from these measurements such as impurity content, ion temperature, rotation, degree of detachment and radiated power depends on calibrated instruments, a physics model of the atomic and molecular processes and plasma transport and an analysis workflow that takes into account environmental effects such as reflections. The particular needs for ITER have prompted a multi-machine, many-year effort to address all these aspects and this chapter reviews the work on diagnostic design, experiments and new analysis techniques. An overview of the laser diagnostics to be implemented on ITER is also provided in this paper. This includes descriptions of the Thomson scattering in the core, edge and divertor regions, polarimetry and interferometry diagnostics used for measuring plasma density and also measurements of helium density in the divertor using Laser Induced Flourescence. Techniques which can allow improvements on current measurements are also addressed in particular expanding poloidal polarimetry measurements to measure field fluctuations and proposed use of dispersion interferometery which has a number of advantages over existing methods. This paper identifies particular areas where further research and testing on existing tokamaks is useful even at this advanced stage to inform the design of diagnostics for ITER. Outstanding areas of concern for the implementation of laser diagnostics, in particular with a view to reliable operation are identified. An overview of the latest developments of microwave diagnostic systems and techniques is given. The primary focus is the contributions for ITER—the next step burning plasma experiment—which is supplemented by describing recent progress of techniques applicable for fusion experiments beyond ITER. The contributions are intentionally kept concise, and are being supplemented by a rich list of references for further studies. Radiation induced effects are receiving continuous and well-deserved attention of the ITER diagnostic community and they are in many cases one of the primary design drivers of the ITER diagnostic systems. The paper summarizes recent progress in this area focusing primarily on the ITER diagnostics but in some cases provides also outlook for the possible solutions for even more demanding radiation environment of fusion reactors beyond ITER. Despite advancements in the area of modeling and simulation of various radiation induced effects, experimental testing in a nuclear environment as close as possible to the target one is still seen as unavoidable for proper qualification of particular diagnostic functional elements. Recent advancement within three diagnostic areas: optical diagnostics, magnetics and bolometers is covered. Encouraging results on qualification of silica glass vacuum window assemblies are presented. In the area of magnetic sensors, progress of irradiation tests performed on ITER in-vessel LTCC inductive sensors is presented with outlook for novel technological approaches to inductive sensors utilizing thick printing and photolithography technologies being highlighted. Summary of advancements in the area of steady state magnetic field sensors based on Hall effect is given. New results of neutron irradiation test of the ITER borosilicate glass inserts for vacuum electrical feedthroughs are summarized finding negligible swelling at target level of neutron fluence. Off-line irradiation tests of fiber optic current sensors for plasma current measurement demonstrated that both for gamma doses up to 5 MGy and a total neutron fluence up to 10 ^15 cm ^−2 , radiation induced changes are still compatible with required measurement accuracy on ITER. The ITER bolometers are given as an example how considering radiation effects may influence the diagnostic design. Finally, outlook for future main R&D directions is outlined. All optical and laser-based diagnostics in ITER will be using mirrors to guide plasma radiation toward detectors, cameras and sensors. In the hostile plasma, radiation and particle environment the optical characteristics of diagnostic mirrors will degrade directly affecting the entire performance of involved diagnostic systems. An assessment of factors affecting mirror performance is provided. Among the prime adverse factors are deposition of plasma impurities, sputtering of mirror surface and steam ingress in the vicinity of mirrors. Within the International Tokamak Physics Activity with active support by ITER central team and domestic agencies, the structured research and development (R&D) program on mitigation of risks for diagnostic mirrors is underway. Within this program the mirror material development, the passive mitigation of mirror degradation by using diagnostic ducts and shutters along with an active mirror recovery program comprising the in-situ mirror cleaning and calibration is underway. Recent developments in diagnostic mirror R&D are described in this Chapter along with an example of their implementation of R&D solutions in ITER Infrared Thermography diagnostic. An assessment of still open engineering and physics questions, considerations on mirror risks during an early phase of ITER operation are given along with an overview of diagnostic mirror evolution in the late ITER operation stage toward the demonstration fusion power plant. Several crucial areas of diagnostic R&D outlined in ITER Research Plan are addressed. The basic control groups in a fusion reactor can be broken-down in five categories: (1) plasma position, magnetic configuration, and plasma current control, (2) profile control and confinement optimization, (3) MHD control and suppression, (4) edge dissipation control, radiation and plasma exhaust control and (5) break-down optimization. These categories are coupled via the physics (a control action in one domain will affect the other domains) and via shared actuators (e.g. ECRH for impurity accumulation avoidance, current density distribution control and MHD suppression). Consequently, a supervisory control system should determine the priority of the various control tasks, their couplings, and the interfaces with the safety and interlock system. For the systematic development of the various controllers taking the complexity of the plasma and the control system into account, a model-based approach is required. A short historical overview is given of the developments in systems and control theory and control engineering with special emphasis on those developments that are most relevant for Nuclear Fusion research and operation. An overview is given of the state of the field of fusion plasma control for the control categories. It will be shown how synthetic diagnostics are being developed in ITER and how they are used in diagnostic design and design validation and how they can be in model-based controller synthesis using relatively simple models. In modern control methods, multiple diagnostics are used to constrain relatively simple models. The constrained models provide an estimate for the state. This opens the route to state controllers, such as model predictive control. A major challenge in nuclear fusion research is the coherent combination of data from heterogeneous diagnostics and modeling codes for machine control and safety as well as physics studies. Measured data from different diagnostics often provide information about the same subset of physical parameters. Additionally, information provided by some diagnostics might be needed for the analysis of other diagnostics. A joint analysis of complementary and redundant data allows, e.g. to improve the reliability of parameter estimation, to increase the spatial and temporal resolution of profiles, to obtain synergistic effects, to consider diagnostics interdependencies and to find and resolve data inconsistencies. Physics-based modeling and parameter relationships provide additional information improving the treatment of ill-posed inversion problems. A coherent combination of all kind of available information within a probabilistic framework allows for improved data analysis results. The concept of integrated data analysis (IDA) in the framework of Bayesian probability theory is outlined and contrasted with conventional data analysis. Components of the probabilistic approach are summarized and specific ingredients beneficial for data analysis at fusion devices are discussed.
Nuclear and particle physics. Atomic energy. Radioactivity
iyad Alumari, Muhanad D. Hashim Almawlawe, Zainab Al-Araji
et al.
In recent years, arrays have been widely used in many applications, especially those applications that need high guidance, whether in military, medical, or other applications. Arrays are highly oriental, unlike single antennas. In this work, we analyze the effect of the insulating substrate insulation constant on the 2X2 microstrip patch antenna array at a frequency of 2.4 GHz, which is suitable for WLAN applications. CST Microwave Studio Version 2019 was used to design, simulate, and analyze the proposed model. The bar line feeding technique was used to feed the array. A set of mathematical relationships was used to calculate the dimensions of the array. We simulated and analyzed the array on three dielectric pillars: (FR-4) with a dielectric constant of 4.3, (Polycarbonate) with an isolation constant of 2.9, and (Porcelain) with an isolation constant of 6. The 2X2 array was manufactured and printed on the insulating substrate (FR-4) and the practical results were compared with the simulation results. There was a good agreement between the practical and theoretical results
In recent years, fiber-reinforced polymers (FRP) have emerged as a highly effective solution for strengthening reinforced concrete (RC) structures. However, accurately assessing the fire resistance of FRP-strengthened members remains a significant challenge due to the limited guidance available in current building codes, often leading to conservative and cost-intensive evaluations. Experimental testing and numerical analysis required for such assessments are resource-demanding, highlighting the need for more efficient methods. This study investigates the application of machine learning (ML) techniques to predict the fire resistance of FRP-strengthened RC beams. Twelve ML models, including eight ensemble methods and four traditional approaches, were employed. The models were trained using a comprehensive dataset comprising over 21,000 data points obtained from numerical simulations and experimental tests. The dataset captured variations in geometric configurations, insulation strategies, loading conditions, and material properties. To enhance predictive accuracy, Bayesian optimization and k-fold cross-validation were applied for model tuning, while the Shapley Additive Explanations (SHAP) method was utilized to assess the relative importance of features influencing fire resistance. Among the models tested, Extreme Gradient Boosting (XGBoost), Categorical Boosting (CatBoost), Light Gradient Boosting (LGBoost), and Gradient Boosting (GRB) demonstrated superior performance, achieving accuracy rates exceeding 92%. Key factors identified as significantly affecting fire resistance included loading ratio, area of tensile reinforcement, insulation depth, concrete cover thickness, and FRP area. The findings underscore the potential of ensemble ML techniques over traditional methods for accurately predicting the fire resistance of FRP-strengthened RC beams, offering critical insights for optimizing design practices and enhancing structural fire safety.
Architectural engineering. Structural engineering of buildings, Structural engineering (General)
Maria Ludovica Ruggeri, Marta Di Nicola, Marzia Passamonti
et al.
<i>Background and Objectives</i>: The aim of the present study is to analyze choroidal and choriocapillaris structural and functional changes in eyes affected by Central serous chorioretinopathy after Photodynamic Therapy (PDT) and Subthreshold Micropulse laser (SML) treatment. <i>Materials and Methods</i>: Forty-two eyes of forty-two patients were analyzed in this observational study. Twenty-four patients underwent SML treatment, whereas eighteen patients were treated with PDT. Examinations were performed at baseline and after 3 months of treatment. Main outcome measures were: Best corrected visual acuity (BCVA), central macular thickness (CMT), central choroidal thickness (CCT), pigment epithelial detachment (PED) presence and maximum height (PEDMH), and choroidal vascularity index (CVI) measured by means of Spectralis HRA + OCT (Heidelberg Engineering, Heidelberg, Germany) Optical coherence tomography (OCT) and choriocapillaris flow voids (CCFV) measured on Optical Coherence Tomography Angiography (OCT-A) platform PLEX Elite 9000 device (Carl Zeiss Meditec Inc., Dublin, CA, USA). <i>Results</i>: Changes in BCVA were registered in both groups over time (<i>p</i> < 0.001). Structural changes in terms of reduced CMT and PED presence were noted in the two groups at follow-up (<i>p</i> < 0.001 and <i>p</i> = 0.001, respectively). Structural and functional choroidal changes were found in the two groups with reduced CCT and CVI over time (<i>p</i> = 0.004 and <i>p</i> = 0.007, respectively), with significant differences between the two groups for CVI parameter (<i>p</i> = 0.001). CCFV increased over time in the PDT group and decreased in the SML group. <i>Conclusions</i>: PDT and SML are effective approaches in CSC eyes and are able to improve structural and functional parameters over time. Choroidal and choriocapillaris parameters are promising biomarkers able to monitor disease course, showing greater impact of PDT on choroid-choriocapillaris complex over time.
CO esterification to dimethyl oxalate (DMO) has important industrial application value. However, the influence of support on catalytic performance has not been investigated sufficiently. In this work, MgAl-LDO supports (MgAl-LDO-400 and MgAl-LDO-600) were prepared at different calcination temperatures. The corresponding Pd-based catalysts was synthesized by impregnation method. The Pd/MgAl-LDO-400 catalyst exhibited higher CO conversion (39%) compared with the Pd/MgAl-LDO-600 (16%). It was found that Pd/MgAl-LDO-400 catalyst contains more Lewis basic sites, which is responsible for its higher activity. This work provides a general understanding of the support effect on catalytic performance induced by the Lewis basic sites.
Anand Elumalai, G. Mohan Ganesh, Kalaichelvan Gurumurthy
In recent years, concrete has become an important versatile construction material. This paper evaluates the strength obtained by concrete with the influence of bacteria. The bacterial strains were isolated from calcareous sludge and urea ware house. The bacterial strains were identified through 16srRNA gene sequencing as Bacillus pumilus and Bacillus flexus. Using these strains, an experiment on cylinder and prisms cast was performed. Compressive strength, split tensile and flexural tests were conducted at the age of 7, 28 and 56 days with ultrasonic pulse velocity and rebound hammer. The results were compared with Bacillus cohnii MTCC 3616 obtained from microbial type culture collection and gene bank, Chandigarh, India. Based on the experimental results, the improvement in the mechanical strength is due to the deposition of calcite crystals on the bacterial cell surfaces within the pores which enhanced the strength of concrete and reduced porosity and permeability.
Engineering (General). Civil engineering (General), Chemical engineering
Natural light is essential in the design of a kindergarten class, but it must also be accompanied by an an artificial lighting system. Therefore using DiaLUX Evo, a kindergarten class was modeled with a specific zoning, where different types of light and building locations depending on the cardinal points were tried. Analyzing the information gathered, it was concluded that the best solution is option 3 in terms of location depending on the cardinal points and in terms of light color it was found that neutral light is optimal for a kindergarten classroom.
Architectural engineering. Structural engineering of buildings, Engineering design
We employed mutual information (MI) analysis to detect motions affecting the mechanical resistance of the human-engineered protein Top7. The results are based on the MI analysis of pair contact correlations measured in steered molecular dynamics (SMD) trajectories and their statistical dependence on global unfolding. This study is the first application of the MI analysis to SMD forced unfolding, and we furnish specific SMD recommendations for the utility of parameters and options in the TimeScapes package. The MI analysis provided a global overview of the effect of perturbation on the stability of the protein. We also employed a more conventional trajectory analysis for a detailed description of the mechanical resistance of Top7. Specifically, we investigated 1) the hydropathy of the interactions of structural segments, 2) the H2O concentration near residues relevant for unfolding, and 3) the changing hydrogen bonding patterns and main chain dihedral angles. The results show that the application of MI in the study of protein mechanical resistance can be useful for the engineering of more resistant mutants when combined with conventional analysis. We propose a novel mutation design based on the hydropathy of residues that would stabilize the unfolding region by mimicking its more stable symmetry mate. The proposed design process does not involve the introduction of covalent crosslinks, so it has the potential to preserve the conformational space and unfolding pathway of the protein.
Vaidas Pribušauskas, Danguolė Plungytė, Kęstutis Lukoševičius
The main aim of the paper is to determine the thermal bridges through which infrared heat is lost through infrared method.
The results obtained during the tests were compared with the technical requirements of construction. Thermovision measurements of window structures were performed in accordance with LST EN 13187:2000. A total of eleven windows operated under real conditions were measured.
The main purpose of the study is to analyze and compare leaks or anomalies in residential window constructions. In residential buildings, windows are the most heat-conductive structures, which makes it difficult to assess their thermal properties. In real-life thermovision studies, it is possible to detect leaks in window structures and to determine the temperature changes of thermal bridges. The data obtained from the direct investigation are compared with the regulatory requirements of the Regulation.
Infrared method was chosen for the study of building window structures, which allows to measure the temperature of structural surfaces of windows under realistic (operational) conditions, without the use of structural dismantling techniques. This is the only method used in civil engineering to get this kind of data.
The main objectives of the research: To determine and compare the design and existing thermal technical characteristics of windows; Investigate invisible, fundamental windows problems that increase heat loss.
During the research, the temperature of the thermal bridges of window constructions was measured with the FLIR B335 thermal imager, and the obtained data was analyzed with the program FLIR Tools.
After detailed measurement of one-window technical indicators and identification of major non-conformities with regulatory requirements, the main focus was on the anomalies identified.
Analyzing the obtained data of thermal bridges, the most conductive places of heat were determined.
Findings of the study:
Investigating the thermal properties of residential window structures from the inside (premises) by infrared method, visually visible heat loss through all structures of the object and thermal bridges could be observed. The intensity of the emitted energy is directly proportional to the body temperature and depends on the radiant power of the body surface.
The problematic locations of the thermal bridges of the sliding partitions of the building are: frame and sash flaps, junction of window sills and reinforced concrete flaps, as well as junction of window block with masonry wall. Surface temperatures do not meet the requirements of the Technical Building Regulations at these locations: frame and sash flap – 91 percent, window sill joint – 64 percent, reinforced concrete lintel joint – 36 percent, window block junction with masonry wall – 27 percent.
The average value of the minimum surface temperatures of the investigated window constructions is 36 percent. does not meet the requirements of the Construction Technical Regulation.
Comparing all the minimum surface temperatures of the studied structures, the maximum heat loss was obtained through the joint of the frame and sash and the window sill joint.
The results of the study could be used in practical / application - oriented ways in the selection and decision making of window installation, maintenance and operation.
CRISAN George-Horea, BODEA Sanda Mariana, JURCO Ancuta-Nadia
et al.
Ensuring the safety and streamline in road traffic are very important aims, with regard to the nowadays people mobility level. Road infrastructure is an essential element that can meet these requirements. Thus, it is proposed to develop an effective model of intersection by using CAD software tools. This type of intersection can be successfully used on almost any category of roads, increasing road traffic safety, reducing passing times through the intersection and in the same time, reducing conflict points and increase the intersection capacity.
Architectural engineering. Structural engineering of buildings, Engineering design
Hao Wu, Marco Antonio Meggiolaro, Jaime Tupiassú Pinho de Castro
The Moment-Of-Inertia (MOI) method has been proposed by the authors to solve some of the shortcomings of convex-enclosure methods, when they are used to calculate path-equivalent ranges and mean components of complex non-proportional (NP) multiaxial load histories. In the proposed 2D version for use with critical-plane models, the MOI method considers the non-proportionality of the projected shear-shear history on each candidate plane through the shape of the load path, providing good results even for challenging non-convex paths. The MOI-calculated path-equivalent shear stress (or strain) ranges from each counted load event can then be used in any shear-based critical-plane multiaxial fatigue damage model, such as Findley’s or Fatemi-Socie’s. An efficient computer code with the shear-shear version of the MOI algorithm is also provided in this work. KEYWORDS. Multiaxial fatigue; Non-proportional loadings; Equivalent ranges; Critical-Plane Approach.
Mechanical engineering and machinery, Structural engineering (General)
Daniel Koscrevic Pandolfo, Jose Antônio Santana Echeverria, Luciano Pivoto Specht
Atualmente é possível dimensionar uma estrutura rodoviária ou um reforço de pavimento através de métodos mecanísticos, podendo se utilizar os métodos empíricos como o do CBR (Califórnia Bearing Ratio) para um pré-dimensionamento. Neste enfoque a estrutura é tratada como qualquer outra em engenharia, como por exemplo, a de concreto armado, onde as tensões e deformações são analisadas e limitadas variando-se dimensões e características dos materiais. Para tratar do reforço de pavimentos, é necessário o prévio conhecimento de algumas características dos materiais existentes na estrutura, como sua rigidez através do módulo de resiliência, o qual pode ser obtido mediante processo de retroanálise das bacias de deflexão. Neste trabalho foi desenvolvido um estudo que buscou retroanalisar dez bacias de deflexão medidas com Viga Benkelman junto à Rodovia BR 472/RS a partir de dois diferentes softwares de retroanálise, e utilizar estes valores em uma análise mecanística propondo diferentes espessuras de reforço em CA (concreto asfáltico). Para cada conjunto de valores de módulo de resiliência obtido foram propostas 6 diferentes espessuras de reforço com MR de 6645 MPa, sendo elas: 4, 7, 10, 13, 16 e 19 cm. Estas estruturas foram analisadas com o software de cálculo de tensões, deformações e deslocamentos AEMC (Análise Elástica de Múltiplas Camadas), a fim de obter a deformação específica de tração na fibra inferior do revestimento e de compressão no topo do subleito. Os valores de deformação foram utilizados nos modelos de desempenho à fadiga de Pinto (1991), Franco (2007) e Federal Highway Administration dos EUA (FHWA), e nos modelos de desempenho de afundamento da trilha de roda do Asphalt Institute dos EUA e Laboratoire Central des Ponts et Chaussées da França (LCPC), afim de estimar o número de solicitações que a estrutura será capaz de suportar sem que ocorra trincamento por fadiga ou deformações maiores que 12,5mm, determinando assim a estimativa de vida útil para cada espessura e conjunto de módulos retroanalisados que foram comparados entre si obtendo a variação de resultados. Complementarmente realizou-se o cálculo da espessura necessária de reforço para a estimativa de vida útil média de fadiga a partir do método PRO 11/79.
Mikolášek David, Lokaj Antonín, Brožovský Jiří
et al.
The paper analyses a drawn steel joint in round logs for which several types of reinforcements have been proposed. The load-carrying capacity of the reinforcements have been tested in laboratories. At the same time, numerical modelling has been performed - it has focused, in particular, on rigidity of the joints during the loading process. Physical and geometrical nonlinearities have been taken into account. The Finite Element Method and 3D computation models have been used in the numerical calculations.
La frattura inizia ad essere considerata oggetto di studio da Leonardo da Vinci e trova in Vannoccio Biringucci ed in Galileo Galilei i precursori di un approccio scientifico al come e perché si produce una rottura. Nell'arco di poco più di un secolo, il sedicesimo, si trovano i primi riferimenti scritti di esperienze e interpretazioni su cui lavorare: i limiti tecnologici e di conoscenza scientifica dei materiali allora disponibili hanno impedito una interpretazione soddisfacente del fenomeno della rottura. Sarebbero occorsi altri due secoli per collegare con una relazione lineare, prima forza e deformazione, e poi tensione e deformazione.
Mechanical engineering and machinery, Structural engineering (General)