Dr. María Jesús Lamela Rey STRUCTURAL MECHANICS DIVISION DEPT. CONSTRUCTION AND MANUFACTURING ENG. FACULTY OF ENGINEERING OF GIJÓN UNIVERSITY OF OVIEDO. SPAIN
University of Oviedo • The University of Oviedo is an institution with more than 400 years of history. It was founded in 1579, but its courses started in 1608. • More than 30.000 students and 3.000 academic staff distributed in three city campuses ( Oviedo, Gijón and Mieres ), • It offers academic programs in all branches of knowledge
• All degrees have been adapted to the European Higher Education Area • The University has done a reorganization of faculties and schools to create great research and teaching centres Faculties Biology Sciences Law Economy and Business Arts Education and Teacher Training Higher Technical Schools Professional Schools Geology Polytechnic School of Engineering Sports Medicine and Medicine and Health Sciences of Gijón (Faculty of Engineering) Physical Education Psichology Polytechnic School of Mieres Computer Engineering Chemistry Polytechnic School of Mining Eng. Commerce, Tourism and Social Sciences Nautical School
Oviedo University International Offers: • Bilingual degrees • International Masters' degrees • Agreements with more than 40 countries • Every year 1,300 grants for study or work placements in more than 400 universities
Faculty of Engineering Campus de Viesques. Gijón Engineering Bachelors: Engineering Masters: - Chemical - Mechatronics and Micro-Mechatronics Systems (Erasmus Mundus Master) - Industrial Technologies - Sustainable Transportation and Electrical Power - Mechanical (Construction and Mechanical Design) Systems (Erasmus Mundus Master) - Electrical - Management of Industrial Design (UPV-UO) - Electronics and Automatics - Energy (UO) - Computer Sciences and Information Technologies - Tecnology and Telecommunication Services
LOCATION
STRUCTURAL MECHANICS DIVISION DEPT. CONSTRUCTION AND MANUFACTURING ENGINEERING FACULTY OF ENGINEERING OF GIJÓN UNIVERSITY OF OVIEDO
Structural Mechanics Division Research Lines: Characterization of materials - Fatigue - Fracture mechanics - Probabilistic models - Biomechanics - Modal analysis - 8
PROBABILISTIC DESIGN MODEL FOR LAMINATED GLASS
1. Introduction Research Project Glass, PN 2005-2008 (EPSIG-UO & ETSII-US) Research Project Glass, PN 2012-2014 (EPIG-UO & ETSII- UPM) � The aim of this research consists of developing a design methodology for monolithic and laminated glass, particularly glazing plates, proposing a new design code for structural glass in Spain. � Due to its brittle nature, glass requires rigorous design methods, since its resistance is very much dependent on surface microcraks, element size and loading pattern. � The design model proposed is developed on the basis of the non-linear plate theory and the elastic and viscoelastic material behaviour of constituents, together with fracture mechanics criteria and probabilistic considerations. 10
2. Description of the design model � Stress model (critical stress) Part I. STRENGTH Part II. LOADING Characterization tests Fracture Load & geometry criteria Weibull cdf, F( σ ) Stress state Critical stress, σ e Part III. PROBABILITY OF FAILURE, P f 11
2. Description of design model Part I. Strength: Glass characterization The characterization of glass can be expressed by the cdf of σ from 4-P bending tests, assuming a 3-parameter Weibull distribution and an area of reference (A ref ) λ 2 L = 0 − + A w 1 L ( ) ref 1 β + σ 1 β σ − λ ( ) σ = σ = − − σ ≥ λ F ( ) P 1 exp ; f , A δ ref β σ − λ ( ) A σ = − − i σ ≥ λ P 1 exp ; f , A δ i A ref 12
2. Description of design model Part I. Strength: Glass characterization Annealed glass 4-P bending test Tempered glass 13
2. Description of design model Part I. Strength: Glass characterization 1 1 0.9 0.9 β = 2.85 β = 9.95 0.8 0.8 λ = 40.88 λ = 84.19 δ = 20.93 δ = 111.9 0.7 0.7 R 2 = 0.9816 R 2 = 0.9159 0.6 0.6 P f [ ] P f [ ] 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0 40 45 50 55 60 65 70 75 80 85 140 150 160 170 180 190 200 210 220 230 σ rot [MPa] σ rot [MPa] Annealed glass Tempered glass 14
2. Description of design model Part I. Strength: PVB viscoelastic characterization • Relaxation test • Creep test Stress Strain Strain Stress Time Time � t σ t ( ) ( ) D t E t � ( ) � ( ) σ � 0 0
2. Description of design model Part I. Strength: PVB viscoelastic characterization T ref = 20 ºC K(t) = 2 GPa DMA RSA3, TA Instruments 16
2. Description of design model Part II. Loading: Finite element analysis (FEA) Metallic support Laminated annealed glass Laminated tempered glass 17
2. Description of design model Part II. Loading Fracture criteria: Part III. Probability of failure (plate) 18
3. Experimental programme � Laminated annealed glass 5 + 5 plates of 1.40 x 1.40 m, e = 6 and 8 mm (v = 3 mm/min) 19
3. Experimental programme � Laminated tempered glass 5 plates of 1.40 x 1.40 m, e = 9 mm (v = 10 mm/min) 20
4. Contrast of results � Laminated annealed glass plates (6 mm) 1,6 Plate 1 1,4 Plate 2 1,2 Plate 3 Load [kN] 1,0 Plate 4 0,8 Plate 5 FEA Encastre 0,6 FEA Pinned 0,4 FEA Pinned (vertical) 0,2 0,0 0 2 4 6 8 10 12 14 16 U z [mm] 100 Pin-support Encastre 80 Experimental data 60 P f [%] 40 20 0 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 Load [N] 21
4. Contrast of results � Laminated tempered glass plates (9 mm) 7 Plate 1 6 Plate 2 5 Load [kN] Plate 3 4 3 Plate 4 2 Plate 5 1 FEA 0 0 20 40 60 80 100 u Z [mm] 100 Point support 80 Experimental data 60 P f [%] 40 20 0 2500 3000 3500 4000 4500 5000 5500 6000 Load [N] 22
BIOMECHANICAL PROPERTIES OF THE TEMPOROMANDIBULAR JOINT DISC
1. Introduction Research Project TMJ, PN 2000-2003 (EPIG,EE-UO & CPS-UZ) Research Project TMJ, CEI 2011-2012 (EPIG,EE-UO & DO-UT) Close Open 24
1. Introduction � The aim of this research consists of developing an experimental programme to simulate the behaviour of biological materials (TMJ discs) under real loading in order to know its biomechanical properties and to propose substitutes materials for implants. 1 2 3 Biomechanical machine, W+B 25
2. TMJ discs characterization DMA RSA3, TA Instruments - Relaxation and creep viscoelastic test in compression - Porcine TMJ discs - T = 37 ºC and saline solution 26
3. Experimental programme Relaxation tests: � � = 5, 10, 15 and 20% � � 1.4x10 6 8x10 5 15% deformación 20% deformación E(t) medial E(t) medial 7x10 5 1.2x10 6 E(t) central 1.2x10 6 E(t) central E(t) lateral E(t) lateral 6x10 5 E(t) posterior E(t) posterior 1x10 6 E(t) anterior E(t) anterior Zona Lateral E(t) 20% 5x10 5 8x10 5 1x10 6 Central E(t) 15% E E 4x10 5 E(t) 10% (Pa) (Pa) 6x10 5 E(t) 5% 3x10 5 8x10 5 4x10 5 2x10 5 2x10 5 1x10 5 E 6x10 5 0.0 0.0 (Pa) 10 -2 10 -1 10 0 10 1 10 2 10 3 10 -2 10 -1 10 0 10 1 10 2 10 3 time (s) time (s) 3.5x10 5 4x10 5 1.6x10 5 10% deformación 5% deformación E(t) medial E(t) medial 1.4x10 5 3x10 5 E(t) central E(t) central E(t) lateral E(t) lateral E(t) posterior 1.2x10 5 2x10 5 E(t) posterior 2.5x10 5 E(t) anterior E(t) anterior 1x10 5 2x10 5 E E 8x10 4 0.0 (Pa) (Pa) 1.5x10 5 10 -2 10 -1 10 0 10 1 10 2 10 3 6x10 4 1x10 5 time (s) 4x10 4 5x10 4 2x10 4 0.0 0.0 10 -2 10 -1 10 0 10 1 10 2 10 3 10 -2 10 -1 10 0 10 1 10 2 10 3 27 time (s) time (s)
3. Experimental programme Creep tests: σ σ = 2.5, 5, 10 and 15 kPa σ σ 4x10 -5 2.8x10 -5 Tensión 10KPa Tensión 15KPa D (t)anterior 8x10 -5 J(t)anterior D (t)posterior J(t)posterior D (t)lateral 2.4x10 -5 J(t)lateral D (t)central J(t)central Zona lateral D (t)medial 3x10 -5 J(t)medial D (t) 2,5KPa 2x10 -5 D (t) 5KPa D D (t) 10Kpa (Pa -1 ) 6x10 -5 D (t) 15KPa 1.6x10 -5 2x10 -5 D 1.2x10 -5 (Pa -1 ) 4x10 -5 1x10 -5 8x10 -6 0.0 100.0 200.0 300.0 400.0 500.0 600.0 0.0 100.0 200.0 300.0 400.0 500.0 600.0 time (s) 7x10 -5 1.1x10 -4 Tensión 5 KPa Tensión 2.5 KPa D (t)anterior D (t)anterior D (t)posterior D (t)posterior 2x10 -5 D (t)lateral D (t)lateral 8.5x10 -5 D (t)central D (t)central D (t)medial D (t)medial 5x10 -5 D (Pa -1 ) D 6x10 -5 (Pa -1 ) 0.0 3x10 -5 0.0 100.0 200.0 300.0 400.0 500.0 600.0 3.5x10 -5 time (s) 1x10 -5 1x10 -5 0.0 100.0 200.0 300.0 400.0 500.0 600.0 0.0 100.0 200.0 300.0 400.0 500.0 600.0 28 time (s) time (s)
4. Master curves fitting process Relaxation Modulus, E(t) 1.2x10 6 E(t) 20% Zona Lateral E(t) experimental 1x10 6 E(t) ajuste Maxwell generalizado de 5 términos 8x10 5 E (Pa) 6x10 5 E(t) 15% 4x10 5 E(t) 10% 2x10 5 E(t) 5% 0.0 10 -2 10 -1 10 0 10 1 10 2 10 3 time (s) n t ∑ E ( t , ) e ( ) exp( ) � � � � o i o � i i 1 � 29
Recommend
More recommend
