3.9Tensile Shear and Clamp Load Tests on High-Tensile ...
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3.9 Tensile Shear and Clamp Load Tests on High-Tensile BOBTAIL Lock Bolts for the Usage in the Steel Industry Problem • Knowledge deficits in using BOBTAIL lock bolts (LB) in high- hfi i i f i (HFGF) i h li d 350 400 maximum force = 367 kN permanent clamp load =307 kN Clamp Load Measurement Bobtail SRB after 24 h (K1‐1‐24h) ´08 - ´10 strength friction grip fastenings (HFGF) in the steel industry. • Influence of the coating (galvanizing, friction coatings) on the loss of clamp load and the load carrying capacity of tensile shear of FP joints with LB is widely unknown. 300 150 200 250 300 Clamp Load [kN] Clamp load after 24 h = 299 kN Clamp load decay - = 8 kN Decay in per cent = 2,62 % Clamp load compulsing process Comlusing process Clamp load after 24h Solution • Determining the sticking friction load by means of double h l ith / ith t t t t f f i ti 23 24 25 Time[h] 0 50 100 0 5 10 15 20 25 30 Time [s] shear samples with / without pre-treatment of friction surfaces by shear tests. • Detecting minimum initial stresses and their decay rate after 24 h and 500 h. • Calculative detection of adhesive friction factor based on Measuring temporal course of clamp load 1“ – BOBTAIL lock bolt 1000 ‐ Force‐stroke‐run of the shear tests series S3 St t f th l ti df ti Benefit test results of qualification of pre-treatment of friction surfaces. 400 600 800 Load [kN] Achieving the sliding performance Start of the dynamic friction Start of the bearing stress strength Start of the plastic deformation of the base material • Possibility of utilization of LB in regulated steel industry according to DIN 18800 and Eurocode 3. • Preparative analyses for acquiring a technical approval for BOBTAIL-SLCP at the German Institute for Structural Quasi static shear F t k h f t il h t t 0 200 0 5 10 15 20 Traverse [mm] Sample 1 Sample 2 Start of the adhesion Engineering (GISE). Quasi-static shear test Force-stroke graph of tensile shear tests Universität Rostock Fakultät für Maschinenbau und Schiffstechnik Lehrstuhl Fertigungstechnik 33 33
Transcript of 3.9Tensile Shear and Clamp Load Tests on High-Tensile ...
3.9 Tensile Shear and Clamp Load Tests on High-Tensile BOBTAIL Lock Bolts for the Usage in the Steel Industryg y
Problem
• Knowledge deficits in using BOBTAIL lock bolts (LB) in high-h f i i i f i (HFGF) i h l i d
350
400
350
400maximum force = 367 kN
permanent clamp load =307 kN
Clamp Load Measurement Bobtail SRB after 24 h (K1‐1‐24h) ´08 - ´10
strength friction grip fastenings (HFGF) in the steel industry.• Influence of the coating (galvanizing, friction coatings) on
the loss of clamp load and the load carrying capacity of tensile shear of FP joints with LB is widely unknown.
150
200
250
300
150
200
250
300
Cla
mp
Lo
ad [k
N]
Clamp load after 24 h = 299 kNClamp load decay- = 8 kNDecay in per cent = 2,62 %
Clamp load compulsing process
Comlusingprocess
Clamp load after 24h
Solution
• Determining the sticking friction load by means of double h l ith / ith t t t t f f i ti
0
50
100
23 24 25Time[h]
0
50
100
0 5 10 15 20 25 30 35Time [s]
shear samples with / without pre-treatment of friction surfaces by shear tests.
• Detecting minimum initial stresses and their decay rate after 24 h and 500 h.
• Calculative detection of adhesive friction factor based on
Measuring temporal course of clamp load 1“ – BOBTAIL lock bolt
1000
‐Force‐stroke‐run of the shear tests series S3
St t f th l ti d f ti
Benefit
test results of qualification of pre-treatment of friction surfaces.
400
600
800
Load
[kN
]
Achieving thesliding performance
Start of the dynamic friction
Start of the bearing stress strength
Start of the plastic deformationof the base material
• Possibility of utilization of LB in regulated steel industry according to DIN 18800 and Eurocode 3.
• Preparative analyses for acquiring a technical approval for BOBTAIL-SLCP at the German Institute for Structural Quasi static shear F t k h f t il h t t
0
200
0 5 10 15 20Traverse [mm]
Sample 1 Sample 2
y
Start of theadhesion
Engineering (GISE).Quasi-static shear
testForce-stroke graph of tensile shear tests
Universität RostockFakultät für Maschinenbau und SchiffstechnikLehrstuhl Fertigungstechnik 3333
