Pomiary odkształceń lokalnych w przestrzeni

• Autorzy: Śmierzchalski R. , Radke M.

Warianty tytułu

EN

Local 3D deformation measurements

• Języki publikacji: PL

Abstrakty

PL

W pracy przeanalizowano dokładność optycznych systemów pomiaru deformacji. Opisano sposób kodowania wielu punktów pomiarowych, budowę systemu do analizy odkształceń, a także dynamikę przyrządu i dostępne zakresy pomiarowe. Zbadano wpływ wielkości próbki na dokładność pomiaru. Porównano wyniki z efektem symulacji z wykorzystaniem MES. Wprowadzono pojęcie naprężeń lokalnych. W ostatniej części wskazano ograniczenia metody i sposoby ich usunięcia. We wnioskach pojawiają się potencjalne aplikacje dla systemu pomiarowego.

EN

Optical systems are becoming more and more popular in quality control, even if there are some physical limitations coming form the light nature. New instruments, that are built by people who can accept those boundaries, are very versatile measuring system. In the first section of this paper a concept of local deformation measurements is presented. The name "local deformation" is used to distinguish it from global deformation [8, 10] occurring between two clearly distant points of any specimen characteristic for typical, mechanical extensometer (Fig. 1). The method for quick marking many measuring points [5] on the surface (Fig. 2) as well as construction and advantages of the system making use of the light reflection to analyze deformation are described. There is also given an answer to the question how to characterize the shape change in dynamic systems. The relationship between the recorder optical configuration and available measuring range as well as the influence of specimen dimensions on the instrument accuracy are characterized [1, 9]. Next, the difference between FEM results and those obtained from real measurements is explained [2, 3]. The notion of local strain [4] was introduced (based on the static deformation of specimen for strength test), which means that the deformation signal was completed by the force signal from a universal testing machine. In the last section of this paper there are considered limitations of the measuring system and a possible way of their elimination. To sum up, the direction of future research is given and the field of deformation (or strain) measuring applications [6,7], including those in which 3D distribution of stress or strain will be necessary, is described.

Słowa kluczowe

PL

odkształcenie; 3D; pomiar optyczny

EN

deformation; 3D; optical measurement

• Wydawca: Wydawnictwo PAK
• Czasopismo: Pomiary Automatyka Kontrola
• Rocznik: 2012
• Tom: R. 58, nr 1
• Strony: 115--118
• Opis fizyczny: Bibliogr. 10 poz., rys., tab., wzory

Twórcy

autor

Śmierzchalski R.

autor

Radke M.

• Politechnika Poznańska, Instytut Technologii Mechanicznej, Zakład Metrologii i Systemów Pomiarowych, pl. Marii Skłodowskiej Curie 5, 60-965 Poznań,

Bibliografia

• [1] Koç M., Billur E., Necati Cora Ö.Ł An experimental study on the comparative assessment of hydraulic bulge test analysis methods. Materials and Design, nr 32, s. 272-281.
• [2] Hogstrom P., Ringsberg J. W., Johnson E. Ł An experimental and numerical study of the effects of length scale and strain state on the necking and fracture behaviors in sheet metals. International Journal of Impact Engineering, nr 36, s. 1194-1203.
• [3] Haghani R. Ł Analysis of adhesive joints used to bond FRP laminates to steel members - A numerical and experimental study. Construction and Building Materials, nr 24, s. 2243-2251.
• [4] Zhua G., Hua X., Kanga J., Mishrab R. K, Wilkinson D. S.: Deformation inhomogeneity in large-grained AA5754 sheets. Materials Science and Engineering, nr 528, s. 4187-4198.
• [5] Kojic M.: An extension of 3-D procedure to large strain analysis of shells. Comput. Methods Appl. Mech. Engrg., nr 191, s. 2447-2462.
• [6] Heinz S. R., Wiggins J. S.: Uniaxial compression analysis of glassy polymer networks using digital image correlation. Polymer Testing, nr 29, s. 925-932.
• [7] Mark N. Helfrick, Christopher Niezrecki, Peter Avitabile, Timothy Schmidt: 3D digital image correlation methods for full-field vibration measurement. Mechanical Systems and Signal Processing, nr 25, s. 917-927.
• [8] Zielnica J.: Wytrzymałość materiałów, Wyd. Politechniki Poznańskiej, Poznań 2001.
• [9] GOM mbH, ARAMIS User Manual, Braunschweig 2007.
• [10] Hegewald und Peschke GmbH, Inspekt Table User Manual, Nossen 2009.