Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582271
Title: Startlink building system and connections for fibre reinforced polymer structures
Author: Zafari, Behrouz
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2012
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Abstract:
The research presented in this thesis examines various aspects on connections and joints in Pultruded Fibre Reinforced Polymeric (PFRP) structures. The work is divided into two experimental investigations on the determination of pin-bearing strength and the characterisation of dowel connections and joint for the Startlink Lightweight Building System (SLBS). To support the development of a strength formula for bearing resistance in bolted connections two pin-bearing strength test series were conducted to study the effects of load orientation and hot-wet conditioning. The limitations of existing standard test methods are exposed from a critical review to show that they do not specify the need for a clearance hole, the range of bolt diameters and PFRP thicknesses found in practice. Because the size of tension coupons is found to be too big to be cut from standard structural profiles an alternative test method, having a smaller coupon size, is needed for every pin-bearing strength to be quantified by testing. Reported in this thesis are test results using an in-house test method that requires a maximum blank coupon of 100 mm × 125 mm. Characteristic strength are determined using Annex D7 of Eurocode 0. Pin-bearing strengths for load orientations of 0, 5, 10, 20, 45 and 90o, to the direction of pultrusion are obtained for a web material taken from a standard wide flange section of 9.53 mm thick. In the test matrix there were four sizes of pin diameter from 9.7 mm to 25.4 mm and a minimum clearance hole of 1.6 mm. The in-house test method is shown to satisfactorily determine pin-bearing strength. Another finding from this study is that the Hankinson formula cannot be applied to establish pin-bearing strength at any orientation on knowing the two characteristic strengths at 0o and 90o. To characterise the effect of hot-wet conditioning 0, 45 and 90o specimens were immersed under water for 3000 hours at 40° C. It is found that the average reduction in characteristic strength is in the range of 18 to 31%. The extent of strength reduction is found to be independent of pin size, except when the diameter is 25.4 mm. The second experimental investigation is for fact finding strength tests towards the application of PFRP dowelling as a method of connection in SLBS. This innovative building system has been engineering for the execution of a FRP house that meets the requirements for code level 6. A series of static coupon-sized tests were conducted to determine the minimum resistance of dowel connections similar to those used in the Startlink house. These results were used to verify the structural engineering design calculations. Another sub-assembly test configuration was used to determine the moment-rotation characteristics of joint details for the portal frame in the SLBS house. Four different beam-to-column joints with dowel connections, and with and without adhesively bonded connections, were statically loaded so that their rotational stiffnesses and modes of failure could be determined. The main conclusions from this study are that: -- all joints had adequate strength against the design ULS moment; -- only when the joint had adhesive bonding between the overlapping beam and column members does the rotational stiffness approach the design rigid condition; -- when clearance holes are present the rotational stiffness is low and applying adhesive bonding around the dowels cannot remove this structural limitation.
Supervisor: Not available Sponsor: Technology Strategy Board (Great Britain)
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.582271  DOI: Not available
Keywords: TA Engineering (General). Civil engineering (General)
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