Nastaran Siahchehreh Soraki, Mohammadreza Bagherzadeh, Yousef Gholipour Kanaani
et al.
Strategic planning is one of the important and effective concepts that organisations have always paid attention to in order to survive, improve competitiveness, adapt to changing environmental conditions and finally provide better services. This issue requires close attention, especially considering the current conditions in important and influential organisations such as the Forensic Medicine Organisation. The purpose of this research is to explain the strategic planning model of the country's forensic medicine organisation through a futures research approach. The research method employed in this study is qualitative. The current research is career-oriented in its purpose and employs both qualitative and survey methodologies. The method of data collection was library studies and semi-structured interviews, and MAXQDA version 20 software was used for data analysis. The statistical population included 15 experts (directors, managers organisation, and supervisors of the organisation's human resource strategy projects, as well as business experts and academic experts in the field of management). The research findings showed that the strategic planning model Forensic Medicine Organisation includes organisational factors, support factors, and individual factors. Organisational factors include cultural, structural, and process criteria. The support dimension includes motivation criteria, an extroverted management team, and a focused management team. Individual factors include interpersonal communication criteria, creativity, and general skills. The results of the research have also shown that strategic futures research operates at two levels of organisation and product employing two approaches: perception and prediction (interpretation). From the perspective of product innovation management, futures research is conducted at both the organisational and product levels. At both levels, environmental monitoring activities, data interpretation and learning are conducted separately.
Dynamic and structural geology, Engineering (General). Civil engineering (General)
Sutikno Sutikno, Sarwono Hardjomuljadi, Hendrik Sulistio
et al.
This research purpose is to offer insights to property owners and developers whose focus tends to be solely on the initial costs of green buildings, and aligning with the requirements set forth by Minister of Public Works and Public Housing Regulation No. 21 of 2022, effective from 2022, which mandates green buildings to obtain Building Structure Approval (PBG) and Functional Worthiness Certificate (SLF). Drawing from the 2013-2018 Green Building Council Indonesia (GBCI) report, which indicates a mere 2% certification rate for buildings exceeding 12 floors, this study seizes the opportunity to delve into how green building considerations influence financial decisions. Surveying 102 experienced respondents in green building practices, this research employs green building factor analysis, value engineering, life cycle cost analysis, and Structural Equation Modeling (SEM)-PLS to scrutinize the factors influencing cost performance in green buildings. The findings spotlight 10 critical green building factors pivotal for securing certification, alongside unveiling correlations between initial costs, operational costs, and life cycle costs. Anticipated outcomes encompass facilitating compliance with Minister of Public Works and Public Housing Regulation No. 21 of 2021, and nurturing the development of green buildings in Indonesia. Implications span regulatory compliance, informed financial strategies, green building advancement, and knowledge dissemination. This study aims to simplify comprehension of the financial ramifications of green buildings, furnishing practical guidance for developers in navigating the intricacies of cost-sustainability equilibrium.
Due to structural limitations, the processes of boring holes are performed in a low-rigidity machining system, which predetermines their susceptibility to vibrations. The article is devoted to the study of the process of boring holes on CNC machines, and the subject of the study is the effect of the cutting mode on the stability of the machining. The mathematical model of the machining system is presented in the form of a two-mass dynamic system, which forms a closed loop structure with negative feedback by elastic displacement. In addition, positive feedback is taken into account through the delay argument function, which represents machining along traces. It has been proven that this process provokes the emergence of regenerative oscillations in the machining system. The application of the system’s approach made it possible to obtain a mathematical model in the form of state variables, which is acceptable for the use of numerical modeling methods in both time and frequency space. An applied engineering program for determining the stability diagram in "cutting depth - spindle speed" coordinates has been created. The program uses a new criterion of stability of systems closed through positive feedback loop with a delay argument function. For the first time, the validity of such a criterion was proved for systems described by differential equations of the fourth order. The importance of taking into account the results of the study in the form of a stability lobes diagram when assigning a cutting mode, especially in the area of high speeds, is proven. Thus, according to the results of the experiments, a change in speed of only 7% from 2150 rpm to 2320 rpm with the same cutting depth of 0.4 mm allows the process to become stable. The use of the created program is possible in the system of automatic control of the online cutting mode when the machine is equipped with vibration sensors with appropriate systems for identifying the dynamic parameters of the machining system, which will significantly increase the machining efficiency.
Ali Ahmed Ajel, Al-Shather Luay Mohammed, Abdul-Jawad Hayder Mahdi
Extended end-plate type connections are widely utilized in steel assemblies for easy production and assembly. The proper end-plate and bolt selection is paramount to confirming safety and economy in all connections and, consequently, steel buildings. This study presented an approach for refined parametric three-dimensional finite element analysis of bolted steel beam-to-beam extended end-plate connections. The model considers geometrical and material non-linearity to determine the impact of various factors on the connection’s performance. The proposed model was used to construct a parametric study. The study variables were bolt diameter and end-plate thickness, focusing on how thick and thin end plates affect connection conductivity. Numerical outcomes demonstrate that the connection's flexural strength and stiffness capability improved by increasing the end-plate thickness and bolt diameter. Finally, the analysis results were assessed, and the main conclusions were presented.
China’s economy has been transitioning from a phase of rapid growth to a stage of high-quality development that is called “new normal,” and China’s construction industry plays a pillar part in China’s economy. Nevertheless, the industry is large but not strong. This labour-intensive industry suffers from low concentration and fierce competition. Based on the organizational theory, which shows how market structure contributes to the growth of industry, this study aims to explore the impact of market concentration and market power on firm’s turnover and profit. Using statistical analysis and panel data of 37 China’s construction companies from 2009 to 2018, this study proposes and calculates the market concentration (CR) and the market power (MP) of China’s companies. Then the augmented Cobb–Douglas production function and OLS regression are used to explore the growth factors of China’s construction industry. The results show that the market concentration increases both the turnover and profit of construction firms. However, market power increases the profit of construction firms while decreases the turnover. In addition, the companies that are China’s non-state-owned have overseas income or are civil engineering and construction have more advantages in the growth of the construction industry in “quality”. This study provides a reference to understand the structures of the construction industries and the structural effect on the growth of different types of firms and could be replicated in other countries with the similar situation.
Alexander Belostotsky, Nikita Britikov, Oleg Goryachevsky
The article compares the requirements for calculating the snow load on the coatings of buildings and structures in accordance with the regulations of technically developed countries and associations – Russia, the European Union, Canada and the United States. It was revealed that in these norms the general approaches, the subtleties of calculating the coefficients, the set of standard coatings and the schemes of the form coefficient proposed for them differ significantly. This situation reflects the general problem of determining snow loads – at the moment there is no recognized unified scientifically grounded approach to determining snow loads on coatings of even the simplest form. The difference in the normative schemes of snow loads is clearly demonstrated by the example of a three-level roof.
Materials of engineering and construction. Mechanics of materials
Extensive site investigations were conducted prior to the construction of a Mass Rapid Transit project in Singapore that was predominantly in the Bukit Timah Granite (BTG) formation residual soil. This paper evaluates the engineering properties of the BTG formation residual soil based on data from 208 site investigation boreholes from four different sites. Based on the results from 2481 conventional laboratory tests and 1192 in-situ tests, this paper summarizes the engineering properties of the highly variable BTG residual soil, including conventional composition analysis, index and hydraulic properties, and strength and deformation parameters required for geotechnical analysis and design. Based on these results, the BTG formation is found to be quite heterogeneous. As the degree of weathering decreases with depth from the top of the formation, the BTG residual soil becomes sandier, with reduced silt and clay fractions. The coefficient of permeability and the compression index of the BTG residual soil vary significantly. In addition, the empirical equations relating the shear strength (index) to the standard penetration test (SPT)-N, as well as the equations and charts for determining stiffness, are proposed. These findings, together with the proposed equations or charts, can be used for design guidance of similar projects related to granitic residual soils in Singapore. Keywords: Bukit Timah Granite, Residual soil, Shear strength, Stiffness, Laboratory testing, In-situ testing
Engineering geology. Rock mechanics. Soil mechanics. Underground construction
Hamdy Abou-Elfath, Ahmed Shamel Fahmy, Khaled Mohamed Khalifa
Over the past two decades, buckling-restrained braces (BRBs) have become increasingly popular as a lateral resisting system because of their capability to provide energy dissipation, stiffness and strength to building structures. Up to date, the Egyptian code has no specifications for estimating the response modification factor (R-factor) of structures equipped with BRBs. The only available alternative for BRB design is to use the R-factor of conventional bracing which is equal to 4.5.This study evaluates the R-factors of low– to mid-rise buckling restrained braced frames (BRBFs) designed according to the Egyptian code. Three BRBFs with 3-, 6- and 12-stories are designed with an R-factor of 4.5. The actual R-factors of the frames are evaluated by conducting static pushover and earthquake time history analyses. The results obtained indicate that the R-factors of the BRBFs considered in this study vary from 5.0 to 13.5 in case of static pushover analysis and from 6.7 to 9.1 in case of earthquake analysis. These static and dynamic ranges of the R-factor are higher than the R-factor of 4.5 specified by the Egyptian code for the design of braced steel frames. Keywords: Buckling-restrained brace, Response modification factor, Egyptian code, Pushover, Earthquake
The invention of Ground Penetrating Radar (GPR) technology has facilitated the possibility of detecting buried utilities and has been used primarily in civil engineering for detecting structural defects, such as voids and cavities in road pavements, slabs and bridge decks, but has not been used to assess the condition of buried pipes. Pipe deterioration can be defined as pipes where, for example, cracking, differential deflection, missing bricks, collapses, holes, fractures and corrosion exists. Assessing the deterioration of underground pipes is important for service efficiency and asset management. This paper describes a research project that focused on the use of GPR for assessing the condition of buried pipes. The research involved the construction of a suitable GPR test facility in the laboratory to conduct controlled testing in a dry sand. Plastic pipes were chosen for the experiments. A series of laboratory experiments were conducted to determine the validity and effectiveness of standard commercially available GPR technology in assessing the condition of buried utilities with common types of damage. Several types of damage to the plastic pipe were investigated with respect to different GPR antenna frequencies. The GPR surveys were carried out in order to obtain signal signatures from damaged and undamaged pipes buried at 0.5 m depth. These surveys were organised on a grid pattern across the surface of the sand in the test facility. The results presented in this paper show that GPR can identify certain types of damage associated with a buried pipe under these controlled laboratory conditions.
Mokadem Salem, Berrahou Mohamed, Mechab Belaïd
et al.
In this study a three-dimensional finite element method analysis of repairing plate with bonded composite patch subjected to tensile load was presented. The effect of the corrosion on the damage of the adhesive (FM73) in the length of inclined crack is presented. The obtained results show that the increase of (DR) is due to the increase of the inclination of the crack against it leads to the decrease of the values of the stress intensity factor in mode I (KI).
Mechanical engineering and machinery, Structural engineering (General)
In order to reveal the differences and conversion relations between the tensile, compressive and flexural moduli of cement stabilized macadam, in this paper, we develop a new test method for measuring three moduli simultaneously. By using the materials testing system, we test three moduli of the cement stabilized macadam under different loading rates, propose a flexural modulus calculation formula which considers the shearing effect, reveal the change rules of the tensile, compression and flexural moduli with the loading rate and establish the conversion relationships between the three moduli. The results indicate that: three moduli become larger with the increase of the loading rate, showing a power function pattern; with the shear effect considered, the flexural modulus is increased by 47% approximately over that in the current test method; the tensile and compression moduli of cement stabilized macadam are significantly different. Therefore, if only the compression modulus is used as the structural design parameter of asphalt pavement, there will be a great deviation in the analysis of the load response. In order to achieve scientific design and calculation, the appropriate design parameters should be chosen based on the actual stress state at each point inside the pavement structure.
Mechanical engineering and machinery, Structural engineering (General)
M. Muñiz Calvente, S. Blasón, A. Fernández Canteli
et al.
Models proposed to study the multiaxial fatigue damage phenomenon generally lack probabilistic interpretation due to their deterministic form. This implies failure compulsory happening at the plane exhibiting the maximum damage value, whereas the remaining planes are disregarded. Nevertheless, the random orientation of the predominant defect evidences the possibility of failure being initiated as a function of the predominant defect presence without requiring, necessarily, maximum values of the damage parameter, which emphasizes the need of introducing probabilistic concepts into the failure prediction analysis. In this paper, a probabilistic model is presented that enables the failure probability to be found for any selected plane orientation by considering the damage gradient as a parameter for both proportional and non-proportional loading. The applicability of the model is elucidated by means of an example. Assuming the cdf for the local failure of the material to be known, the probability of failure is calculated for a cross shaped specimen in which shift between the principal stresses sigma xx and sigma yy ranges from 0º to 180º.
Mechanical engineering and machinery, Structural engineering (General)
Lately, more often, speaks about forms design, the concept that comprising, approach, in terms of natural, of triad
- Aesthetics,
- Architecture,
- Engineering.
The shapes are geometric aspects of all manifestations of the material world or from our three-dimensional world. As well we can talk about forms carrier of energy and information.
Architectural engineering. Structural engineering of buildings, Engineering design
Paulo N.B. Reis, José A.M. Ferreira, José D.M. Costa
et al.
This paper describes an experimental study developed to characterize the mode I and mode II
fracture toughness of carbon/epoxy woven composites, using DCB and ENF tests, respectively. The laminates
were manufactured using an epoxy resin and twelve woven balanced bi-directional layers of carbon fibres, all of
them with the same orientation (0/90º). Significant instantaneous delaminations were observed particularly for
the DCB specimen, which were responsible for an oscillatory behaviour of GI versus crack length. The
maximum values obtained for GIC and GIIC were 281 and 1800 J/m2, respectively.
Mechanical engineering and machinery, Structural engineering (General)
This paper considers an important topic, and one that is often poorly understood or misinterpreted, but which is a determining factor in many aspects of the service performance of metals (and other materials). Engineering components and structures must, of necessity, provide a bridge between the macroscopic, homogeneous and generally continuum aspects of applied load and displacement, and the microscopic, heterogeneous and often non-continuum reality of material structure and behaviour. This bridge can take the form of a genuine interface between material and environment, e.g. at a surface, or can be a virtual one where the differing philosophies of design have to be merged. The interface has particular importance in circumstances where environmental influences have a key role in determining performance characteristics (e.g. creep, environmentally-assisted cracking, or corrosion), where performance is dominated by fatigue or fracture, where welding is used to join components, or where tribology plays a role. The paper focuses on the problems associated with cracking and uses case study examples drawn from engineering practice to illustrate the role of metallurgical factors in mechanical performance of materials.
Mechanical engineering and machinery, Structural engineering (General)
Il lavoro sintetizzato nel presente articolo si pone come obiettivo primario quello di investigare lapossibilita di stimare, mediante un approccio elasto-plastico agli elementi finiti, la durezza dei materiali metalliciconvenzionali, e questo sia a livello macroscopico, che a livello microscopico, che, infine, a livello nanoscopico.Per verificare validita e accuratezza della metodologia FEM sviluppata, sono state condotte una serie di analisisperimentali su tre materiali metallici aventi caratteristiche metallurgiche estremamente diverse: una legadfalluminio (Al 7075-T6), un acciaio a basso tenore di carbonio (BS970-En3B) e, infine, un acciaio austenitico(AISI 316L). Lfindentazione Vickers e stata simulata con analisi elasto.plastiche agli elementi finiti considerandocarichi di prova nellfintervallo tra 490 N e 490 ƒÊN e calibrando le simulazioni numeriche mediante curvemonotone tensione.deformazione ottenute da prove di trazione eseguite utilizzando provini sia di dimensioneconvenzionale che aventi larghezza della zona calibrata dellfordine dei 100 ƒÊm.La sistematica comparazione tra risultati sperimentali e simulazioni numeriche ha posto in evidenza comelfaumentare del valore della durezza misurata al diminuire della dimensione dellfimpronta possa essere imputataal ruolo giocato dalla reale morfologia del materiale, ruolo che diventa predominante sulla plasticitaconvenzionale quando le dimensioni della superficie indentata diventano comparabili con le dimensioni mediedella grana cristallina delle leghe esaminate. Tali fenomeni, pertanto, non hanno consentito di estenderelfutilizzo della meccanica del continuo fino ad un livello nanoscopico per determinare correttamente i valoridella durezza. Alla luce di questi risultati e stata, pero, proposta una semplice metodologia di correzione dellestime eseguite mediante gli elementi finiti che si e dimostrata un valido strumento da utilizzarsi in situazioni diinteresse pratico per stimare la durezza dei materiali metallici, indipendentemente dalla dimensione dellasuperficie indentata.
Mechanical engineering and machinery, Structural engineering (General)