2017cez7521 - Design Of Flexible End Plate Connection.pptx

CVL 761 Theory of Steel Structures – Term Project

Design of Flexible End Plate Connections Presented By:

ABHISHEK JAIN 2017CEZ7521

1. Simple Connections Connections are designed to just transfer Shear force and Axial force from the connecting member to primary member

Shear Tab connection

(IS 800, 2007)

2. Semi-Rigid Connections Connections designed to transfer complete shear force, axial force and partial moment from the connecting member

3. Rigid Connections Connections designed to transfer complete shear force, axial force and complete moment from the connecting member (IS 800, 2007)

Flexible end plate Connection (Steel Construction Institute, 2017)

Extended end plate Connection (Maris, 2015)

Applicability

• Flexible end plates can be used in all simple connections • Ideal for beam to beam connections where the secondary beams are there on both sides

• One of the cheapest connections due to minimum eccentricity

Simplicity of Design

• No additional eccentricity as the bolts are in the same plane as the bolts

• Less flexibility in design where two beams of different depths are being connected on the either side

• Erection Issues when connected to the web of the column (For Columns greater than 10 m in height without splicing)

• Costlier bolts to be used if connected to a hollow section

(Steel Construction Institute, 2017)

(Lindapter, 2015)

For partial depth end plates, there are two stages

1. The unhindered rotation of connection 2. The lower flange bears against the support

(Steel Construction Institute & The British Constructional Steelwork Association 2002, 2002)

1. Beam Web Strength Check (If coping is done) 2. Weld check 3. End plate check 4. Bolt Check

FORCES FOR DESIGN

(Steel Construction Institute & The British Constructional Steelwork Association 2002, 2002)

1. Beam web check

Vd =

𝐷𝑡𝑤 𝑓𝑦 3𝛶𝑚𝑜

The beam web is coped when it is connected to another beam. The shear check needs to be done for the reduced depth D

2. Bolt Capacity check

2.1 Bolt locations a) End distance & edge distance is greater than 1.5 x dia of the hole

b) Pitch and gauge is greater than 2.5 times the dia of hole c) The maximum distance between two bolts should be less than 32 t or 300 mm, whichever is lesser

2.2 Bolt Shear capacity check 𝑓𝑢 (𝑛𝑛 𝐴𝑛𝑏 +𝑛𝑠 𝐴𝑠𝑏 ) Vdsb = 3𝛶𝑚𝑏

(University of Exeter, UK, 2017)

2.3 Bolt Bearing capacity check 2.5𝑓𝑢 𝑘𝑏 𝑑𝑡 Vdpb = 𝛶𝑚𝑏

3.0 Fillet Welding Check 𝐾 𝑡𝑤𝑒𝑙𝑑 𝐿𝑤𝑒𝑙𝑑 𝑓𝑤𝑛 Vwd = 3𝛶𝑚𝑤

𝛶𝑚𝑤 = 1.25 𝑓𝑜𝑟 𝑠ℎ𝑜𝑝 𝑤𝑒𝑙𝑑𝑖𝑛𝑔 𝛶𝑚𝑤 = 1.5 for site welding

4.0 End Plate Strength Check Vplate =

𝑡𝑝 (𝐷𝑝 −𝑛𝑑𝑜 )𝑓𝑦 3𝛶𝑚𝑜

𝐷𝑝 = 𝐷𝑒𝑝𝑡ℎ 𝑜𝑓 𝑒𝑛𝑑 𝑝𝑙𝑎𝑡𝑒 n= 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑜𝑙𝑡𝑠 𝑖𝑛 𝑜𝑛𝑒 𝑐𝑜𝑙𝑢𝑚𝑛 𝑑𝑜 = 𝑑𝑖𝑎 𝑜𝑓 𝑡ℎ𝑒 𝑏𝑜𝑙𝑡 ℎ𝑜𝑙𝑒

Beam-Beam Flexible end plate connections If supporting beam is free to rotate then there will be adequate rotational capacity in connection even with thick plates. If supporting beam is not free to rotate then there will be adequate rotational capacity even with thick plates leading to:

1. Large Prying Forces 2. Overstressing of bolts and welds

(Steel Construction Institute & The British Constructional Steelwork Association 2002, 2002)

As per BS 5950, Structures are required to have a minimum robustness to resist accidental loading. One method of achieving this is by tying all the principal elements of a structure together . The minimum tying force for which end plate connection must be designed is 75 kN

(BS 5950-1, 2000)

BS 5950-1, 2000. Structural use of steelwork in building. London: British Standards. IS 800, 2007. GENERAL CONSTRUCTION IN STEEL - CODE OF PRACTICE. NEW DELHI: BUREAU OF INDIAN STANDARDS. Lindapter, 2015. Type HB Hollo-Bolt, Yorkshire: Lindapter International. Maris, C. &. V. C. &. S. A. &. D. D., 2015. Validation through numerical simulations of the design procedure for bolted beam-to-column connections with haunches. Pollack Periodica. , pp. 10. 95-107. 10.1556/606.2015.10.3.10. Steel Construction Institute & The British Constructional Steelwork Association 2002, 2002. Joints in Steel Construction: Simple Connections. First Edition ed. London: Steel Construction Institute & The British Constructional Steelwork Association 2002. Steel Construction Institute, 2017. Simple Connections. [Online] Available at: https://www.steelconstruction.info/Simple_connections#Flexible_end_plate_connections [Accessed 15 April 2018]. Subramanian, N., 2016. Bolted Connections. In: Design of Steel Structures. New Delhi: Oxford University Press, pp. 186-238.

University of Exeter, UK, 2017. Solid Mechanics, Lecture 3. [Online] Available at: http://people.exeter.ac.uk/TWDavies/solid%20mechanics/lecture%203/Lecture%203.htm [Accessed 17 April 2018].