BIM: a technology acceptance model in Peru

The purpose of this paper is to empirically study factors that facilitate the adoption of building information modelling (BIM) among practitioners using the unified theory of technology acceptance model (TAM). The factors identified in the TAM were examined using a quantitative approach. The empirical investigation has been conducted using a survey questionnaire. The data set has been obtained from 73 architects and engineers in Peru. Results show that Perceived Usefulness (PU) is the most important determinant of Behavioural Intention (BI), while Perceived Ease of Use (PEOU) is found to have no significant effect on BI. The findings provide an excellent backdrop in the development of policy and a roadmap for BIM implementation in Peru. The original contribution and value of the paper is the use of TAM to provide empirical evidence on factors that facilitate BIM adoption in Peru

Installation of offshore wind turbines: A technical review

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DESIGN OPTIMIZATION OF MOVEABLE MOMENT STABILIZATION SYSTEM FOR ACCESS CRANE PLATFORMS

The popularity of aerial work platforms is rapidly increasing in the mechanization industry. As a result, the safety and structural strength of aerial work platforms should be prioritized.In this study, the mathematical model of a reconstructed aerial work platform was developed and a 3D model was created using the Solidworks software. A dynamic analysis was then performed to improve various structural parameters of the aerial work platform. The analysis was carried out using solid modelling, finite elements, and dynamic transient analysis. In compliance with international structural standards, the weight distribution was reconstructed after placing a mass behind the turret.The results of the dynamic transient analysis were compared with the mathematical model and validated. Then, the effect of the mass placed behind the turret on the machine was examined. The lateral tipping distance of the static work platform was found to have increased from 15.9m to 17.08 m. The structure of the aerial work platform was improved using a structural and dynamic analysis approach. It was also discovered that the machine efficiency could be further increased by ensuring that the balancing weight is moved further away from the tower centre by a hydraulic-based system and controller

EVALUATING THE SEISMIC EFFECTS ON LIFTING EQUIPMENT

The purpose of this paper is to assess the dynamic behaviour of various lifting equipment (different types of cranes, elevating work platform, etc.) subjected to seismic actions, evaluating how these actions can both generate failures and affect the structural behaviour of the machine. The work is developed starting from the design of the different machines of interest (according to some classical standards and specific performance like working load, lifting speed, working area, etc.), determining their geometry. Subsequently are applied the characteristic load spectra to the structures, related to the magnitude of earthquake; the final step consist in the structural analysis of the machines, computing their maximum stresses, displacements and natural frequencies, using different finite element codes. The results show that the first natural frequencies of the structures are very low and consequently the effects of the seismic action, in general, are not dangerous. Otherwise it is important to underline that the maximum stress induced by the earthquake is detectable in different position in the lifting equipment respect to maximum stress position in the normal loading operations, therefore seismic analyses are indispensable for study these parts of machines

Sway Reduction of Tower Crane

Tower crane is a common fixture at any major construction site. They often rise hundreds of feet into the air, and can reach out just as far. Tower crane has a problem that a fast transfer of the load causes sway of the load. It takes a long time sometime to lift up and unload the load due to the wind and other disturbances. The objective of this project is to minimize the sway of the load suspended on the tower crane by developing a control method by using a concept of spherical pendulum and delayed position feedback. Develop equation for controller and solve using numerical simulation. From the result gained, the best method can be used to minimize the sway of the tower crane

ANALYTICAL AND EXPERIMENTAL VIBRATION ANALYSIS OF TELESCOPIC PLATFORMS

In this study, vibration analysis of a telescopic platform is conducted, and the platform structure is reconstructed to satisfy vibrational standards. The analysis is realised using solid modelling, finite elements and an analytical method. The results are verified using experimental modal techniques. Through the finite element and experimental modal approach free vibration analysis is carried out and natural frequencies are determined. Additionally, vibration accelerations of the structure are obtained by forced vibration analysis of the model. All calculations one performed on the new reconstructed structure, and it is determined whether the reconstructed structure satisfies the vibrational standards

Consideration of moving oscillator problem in dynamic responses of bridge cranes

U radu je razmatrano dinamičko ponašanje noseće konstrukcije mosne dizalice usled dejstva ovešenog tereta na kolicima koja se kreću determinisanom brzinom. Glavni nosač je modeliran kao greda podeljena na 10 elemenata, kolica kao pokretna masa i teret kao masa, koja je ovešena na kolica sistemom užadi modeliranim oprugom. Matrice inercije, prigušenja i krutosti se računaju za svaki vremenski interval, a ekvivalentno spoljašnje opterećenje grede je formulisano kroz konačnoelementni pristup problemu. Jednačine kretanja sistema sa konačnim brojem stepena slobode su prikazane za model pokretnog oscilatora koji se kreće determinisanom brzinom po grednom nosaču. Dinamički odziv (ugib, brzine, ubrzanja) za sve stepene slobode je dobijen rešavanjem jednačina numerički, metodom direktne integracije. Verifikacija celog algoritma je data kroz poređenje rešenja za dinamički ugib proste grede pod dejstvom pokretne sile koja se kreće konstantnom brzinom. U radu je razmatran uticaj brzine kretanja kolica i krutosti opruge na dinamičko ponašanje noseće konstrukcije dizalice.The dynamics of an overhead crane system with the suspended payload on the trolley moving at a specified constant speed is considered in this paper. The beam is discretizied by 10 elements, while the trolley is modeled as particle along with payload suspended with rope system modeled as spring. The overall mass, damping and stiffness matrix is calculated at each time interval, along with finite element formulation of equivalent force vector. Equations of motion of MDOF system are given for oscillator moving on beam structure. Dynamic responses in the vertical direction for all DOFS are obtained by solving the governing equations with direct integration method. For validation purposes, the technique is first applied to a simple beam subjected to a force moving along the beam with constant velocity. The influence of moving velocity and spring stiffness are investigated

Consideration of moving oscillator problem in dynamic responses of bridge cranes

U radu je razmatrano dinamičko ponašanje noseće konstrukcije mosne dizalice usled dejstva ovešenog tereta na kolicima koja se kreću determinisanom brzinom. Glavni nosač je modeliran kao greda podeljena na 10 elemenata, kolica kao pokretna masa i teret kao masa, koja je ovešena na kolica sistemom užadi modeliranim oprugom. Matrice inercije, prigušenja i krutosti se računaju za svaki vremenski interval, a ekvivalentno spoljašnje opterećenje grede je formulisano kroz konačnoelementni pristup problemu. Jednačine kretanja sistema sa konačnim brojem stepena slobode su prikazane za model pokretnog oscilatora koji se kreće determinisanom brzinom po grednom nosaču. Dinamički odziv (ugib, brzine, ubrzanja) za sve stepene slobode je dobijen rešavanjem jednačina numerički, metodom direktne integracije. Verifikacija celog algoritma je data kroz poređenje rešenja za dinamički ugib proste grede pod dejstvom pokretne sile koja se kreće konstantnom brzinom. U radu je razmatran uticaj brzine kretanja kolica i krutosti opruge na dinamičko ponašanje noseće konstrukcije dizalice.The dynamics of an overhead crane system with the suspended payload on the trolley moving at a specified constant speed is considered in this paper. The beam is discretizied by 10 elements, while the trolley is modeled as particle along with payload suspended with rope system modeled as spring. The overall mass, damping and stiffness matrix is calculated at each time interval, along with finite element formulation of equivalent force vector. Equations of motion of MDOF system are given for oscillator moving on beam structure. Dynamic responses in the vertical direction for all DOFS are obtained by solving the governing equations with direct integration method. For validation purposes, the technique is first applied to a simple beam subjected to a force moving along the beam with constant velocity. The influence of moving velocity and spring stiffness are investigated

Considerations of various moving load models in structural dynamics of large gantry cranes

Rad se bavi problematikom pokretnog opterećenja kod portalnih dizalica visokih performansi. Usvojen je kombinovani pristup, koji podrazumeva primenu metode konačnih elemenata u kombinaciji sa jednačinama analitičke mehanike, za formiranje matematičkih modela portalne dizalice. Model kolica je razmatran kroz nekoliko modela: pokretna sila, pokretna masa, pokretni oscilator i pokretni oscilator sa klatnom. Svaki od modela ima svoje dinamičke karakteristike koje profilišu dinamički odziv strukture dizalice. Rešenja su dobijena numerički, metodom direktne integracije, razmatranjem ravanskog ramovskog konačno elementnog modela strukture pod dejstvom ekvivalentnog pokretnog opterećenja na osnovu postavljenog sistema diferencijalnih jednačina drugog reda sa promenljivim koeficijentima. Prikazana je problematika koja nastaje pri povećanju broja parametara pri formiranju dinamičkog modela-postavci matematičkog modela. Na realnom primeru dizalice su dati dinamički odzivi različitih modela koji mogu poslužiti kao preporuka za izbor modela u zavisnosti od važnosti željenih dinamičkih parametara u fazi projektovanja kontejnerskih dizalica.The paper deals with the moving load problems within the structural dynamic analysis of a large gantry crane as high-performance machine. The emphasis is placed on combined method approach, i.e. finite element method and analytical postulations, to obtain the mathematical model of crane. Moving trolley is considered throughout several models: moving force, moving mass, moving oscillator and moving oscillator with swinging object. Each model has characteristics which determine the responses of the crane structure, along with its dynamic properties. The title problem is solved by calculating the forced vibration responses of the two-dimensional framework with time-dependent property matrices and subjected to an equivalent moving load. Improving the moving load models increases complexity as well for postulating as for obtaining the solutions from overall crane model. Comparative presentation of models is shown here with conclusion that leads to an appropriate way of model selection prior to crane problem postulation