Abstract | U ovome radu određene su dimenzije konstrukcije u skladu sa dopuštenim opterećenjima, kroz statičke proračune sila i momenata te kroz glavne principe čvrstoće. Polazište rada bio je upit kupca sa okvirnim dimenzijama i izgledom, sa unaprijed poznatim i definiranim maksimalnim opterećenjem. Prikazana je izrada statičkog proračuna i konstruiranje nosive konstrukcije sa unaprijed poznatim i definiranim maksimalnim opterećenjem. U radu je kroz deset dijelova, cjelovito prikazan odabir materijala temeljen na čvrstoći i statici, te proračun nosivih elemenata sa stajališta sile, momenata i pomaka same konstrukcije. Objašnjeni su glavni pojmovi statike kao što su sila, moment, težište, rezultanta i ravnoteža. Kroz metode deskripcije, analize, sinteze te indukcije i dedukcije objašnjeni su osnovni pojmovi statike, kao i njihova primjena na konkretnom primjeru izrade konstrukcije kapije ulaznih vrata, kao i vrste opterećenja, razlika između rešetkastih i punih nosača, izbor materijala uz poseban naglasak na Youngov modul elastičnosti materijala i Wohlerovu krivulju, koji su korišteni pri izradi konstrukcije kapije (S355JR čelik prema standardu UNI EN 10027-2; C55 čelik prema standardu UNI EN 10083-2). Pri dimenzioniranjima je korištena metoda dimenzioniranje putem kriterija čvrstoće, te su elementi i materijali odabrani i prilagođeni tom kriteriju. Kako naposljetku računski prihvatljiva izvedba ove kapije iznosi oko 320 kg, a cijena čelika prema londonskoj burzi (za posljednjih 6 mj.) iznosi u prosjeku 1 €/kg, cijena utrošenog materijala potrebnog za izradu iznosi 320 €. |
Abstract (english) | This paper outlines the defining and dimensioning process on a construction defined by allowable loads, as well as static calculations of forces and moments and the key principles of strength of materials. The starting point of this paper, and work, was an enquiry from a client, containing approximate measures and visuals, with the maximum force defined from the start. This paper summarizes the making of a static calculation of the supporting structure of a gate to a yard belonging to a private house, taking into consideration the look and approximate dimension. Material selection was made according to principles of statics and strength of materials, and the calculus was made taking into consideration the forces, torque, balance and all possible shifts of the construction during the exploitation. All the static key points were explained thoroughly, along with application on a certain example. This paper outlines all the static terms through the methods of description, analysis, syntheses, along with deduction and induction thinking. A brief overview was made on material selection and how to choose the correct one, with special attention to Young modulus and Wohler’s curve (the steel grade used for this project is S355JR, according to the UNI EN 10027-2 standard, along with C55 steel according to the UNI EN 10083-2). For the dimensioning processes, the method of dimensioning by strength criteria was chosen, and all the materials and dimensions were chosen or corrected by the same criteria. The acceptable solution for this gate weighed approximately 320 kg, and since the price of steel for the last 6 months according to the LME equals around 1 €/kg, we can say that the price for this projects' raw materials equals 320 €. |