Material Behaviour of 109 Bolts under Fire Conditions Fernando Gonzalez/Jörg Lange
Connection Design According the EC3 Annex D
Connection Design According the EC3 Annex D - Step 1: Determination of the steel temperature in the connection Δ λp Ap V ( θ g, t θa, t ) θ, Δθ = a t = k shadow Am V h& c ρ a a net Δt φ 10 ( e ) Δθ g, t a, t Δt 1 d pcaρa ( 1+ φ 3) - Step 2: Determination of the strength reduction factors for bolts 1,00 0,80 f 8 / f20 C 0,60 0,40 0,20 0,00 Reduktionsfaktoren EC 3 Schrauben Reduktionsfaktoren EC 3 Stahl 0 100 200 300 400 500 600 700 800 Temperatur [ C] - Step 3: Design of the connection using the reduction factors
Designing Hot Connections Fin plate connection 135/70/30; HEA 200 Temperaturentwicklung 800 Temperatur [ C] 600 400 200 0 ETK Gastemp Versuch Temp Profil Versuch Temp Anschluss Versuch 0 5 10 15 20 25 30 Zeit [min ]
Designing Hot Connections Fin plate connection 135/70/30; HEA 200 Temperaturentwicklung 800 A Trägermitte : 53,8 cm² U Trägermitte : 113,6 cm => U/A: 211,8m -1 k sh : 0,68 A Anschluss : 94,3 cm² U Anschluss : 119,6 cm => U/A: 126,8m -1 => k sh : 0,65 Temperatur [ C] 600 400 200 0 0 5 10 15 20 25 30 Zeit [min ] ETK Gastemp Versuch Temp Profil Versuch Temp Anschluss Versuch Temp Profil gerechnet
Designing Hot Connections Fin plate connection 135/70/30; HEA 200 Temperaturentwicklung 800 A Trägermitte : 53,8 cm² U Trägermitte : 113,6 cm => U/A: 211,8m -1 k sh : 0,68 A Anschluss : 94,3 cm² U Anschluss : 119,6 cm => U/A: 126,8m -1 => k sh : 0,65 Temperatur [ C] 600 400 200 0 0 5 10 15 20 25 30 Zeit [min ] ETK Gastemp Versuch Temp Profil Versuch Temp Anschluss Versuch Temp Profil gerechnet Temp Anschluss gerechnet
Designing Hot Connections End plate connection Temperaturentwicklung 800 A Trägermitte : 53,8 cm² U Trägermitte : 113,6 cm => U/A: 211,8m -1 k sh : 0,68 A Anschluss :? cm² U Anschluss :? cm Temperatur [ C] 600 400 200? ETK => U/A:? m -1 0 0 5 10 15 20 25 30 Zeit [min ]
Testing Methods Steady State Tests and Transient State Tests according Anderberg T = const TRANSIENT STATE TESTS RESTRAINT FORCES FAILURE TEMPERATURE Total deformation ε = const σ = const RELAXATION CREEP STEADY STATE TESTS T = const STEADY STATE TESTS STRESS-STRAIN RELATIONSHIP Strain rate controlled STRESS-STRAIN RELATIONSHIP Stress rate controlled ε = const σ = const
Testing Methods Steady State Tests and Transient State Tests according Anderberg T = const TRANSIENT STATE TESTS RESTRAINT FORCES FAILURE TEMPERATURE Total deformation ε = const σ = const RELAXATION CREEP STEADY STATE TESTS T = const ε = ε el + ε pl STRESS-STRAIN RELATIONSHIP Strain rate controlled STRESS-STRAIN RELATIONSHIP Stress rate controlled STEADY STATE TESTS ε = const σ = const
Testing Methods Steady State Tests and Transient State Tests according Anderberg T = const TRANSIENT STATE TESTS RESTRAINT FORCES FAILURE TEMPERATURE Total deformation ε = const σ = const RELAXATION CREEP STEADY STATE TESTS T = const ε = ε cr STRESS-STRAIN RELATIONSHIP Strain rate controlled STRESS-STRAIN RELATIONSHIP Stress rate controlled STEADY STATE TESTS ε = const σ = const
Testing Methods Steady State Tests and Transient State Tests according Anderberg T = const TRANSIENT STATE TESTS RESTRAINT FORCES FAILURE TEMPERATURE Total deformation ε = const σ = const RELAXATION CREEP STEADY STATE TESTS T = const ε = ε el + ε pl + ε cr + ε th STRESS-STRAIN RELATIONSHIP Strain rate controlled STRESS-STRAIN RELATIONSHIP Stress rate controlled STEADY STATE TESTS ε = const σ = const
Material Bolt type Minimum tensile strength [N/mm²] Minimum strength at 02% [N/mm²] Min ult strain [%] Necking [%] Vickers hardness, HN; F 98 N 109 1040 940 9 48 min 320; max 380
High Temperature Test Testing device Thermocouples Extensometer Specimen
High Temperature Test Results of the steady state tests Stress- Strain Curves 1000 800 Stress [N/mm²] 600 20 C 400 200 C 300 C 400 C 200 500 C 600 C 700 C 0 0,00 0,40 0,80 1,20 1,60 2,00 Strain [%] Strain rate: 0,001 min -1 Heating rate: 10 K/min
High Temperature Test Results of the steady state and transient state tests Stress- Strain Curves 1000 Stress [N/mm²] 800 20 C 200 C 600 300 C 400 C 500 C 400 600 C 700 C 200 Trt 200 C Trt 400 C Trt 500 C 0 0,00 0,40 0,80 1,20 1,60 2,00 Strain [%]
High Temperature Test Comparison of the results 1,00 0,80 tensile strength ratio Reductionfactor acc EC 3 f θ / f 20 C 0,60 0,40 0,20 0,00 0 100 200 300 400 500 600 700 800 900 Temperature [ C]
High Temperature Test Stress- Strain Curve at 600 C 300 250 Tensile strength Stress [N/mm²] 200 150 100 50 ε& = 0,001m ε& = 0,025m 1 1 0 600 C 0 2 4 6 8 10 12 14 16 18 20 Strain [%]
High Temperature Test Comparison of the results Reduktionsbeiwerte 1,00 0,80 tensile Zugfestigkeitsverhältnis strength ratio strength Festigkeitsverh ratio at 2% bei strain 2% Reductionfactor Reduktionsfaktor acc EC3 3 f θ / f 20 C 0,60 0,40 0,20 0,00 0 100 200 300 400 500 600 700 800 900 Temperature [ C]
High Temperature Test Comparison of the results 1,00 0,80 tensile Zugfestigkeitsverhältnis strength ratio strength Festigkeitsverh ratio at 2% bei strain 2% Reductionfactor ReduktionsfaktorEC acc EC 3 3 f θ / f 20 C 0,60 0,40 0,20 0,00 overestimation of the bearing capacity 0 100 200 300 400 500 600 700 800 900 Temperature [ C]
Tests on Bolts Thread failure at room temperature Bolt failure at high temperatures
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