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Enquist, Bertil
Publications (7 of 7) Show all publications
Bader, T. K., Vessby, J. & Enquist, B. (2018). Path dependence in OSB sheathing-to-framing nailed connection revealed by biaxial testing. Journal of Structural Engineering, 144(10), Article ID 04018197.
Open this publication in new window or tab >>Path dependence in OSB sheathing-to-framing nailed connection revealed by biaxial testing
2018 (English)In: Journal of Structural Engineering, ISSN 0733-9445, E-ISSN 1943-541X, Vol. 144, no 10, article id 04018197Article in journal (Refereed) Published
Abstract [en]

OSB sheathing-to-wood framing connection, as typically used in light-frame shear walls, was experimentally examined in a novel biaxial test setup with respect to possible path dependence of the load-displacement relation. The connection with an annular-ringed shank nail was loaded under displacement control following nine different displacement paths within the sheathing plane, which coincided at a number of points. In intersection points, resultant connection force, its orientation and work performed on the connection system to reach the specific point were calculated and compared. Evaluation of experiments revealed significant path dependence with respect to orientation of force resultants at path intersection points. However, magnitude of the forces and the work carried out showed relatively small dependence of the displacement path undertaken. Comparison of uniaxial connection tests with the European yield model demonstrated strong contribution of withdrawal resistance of the ringed shank nail to its lateral strength. Results of this type are a valuable basis to build better models when simulating such connections in wood structures.

Place, publisher, year, edition, pages
Reston, VA: American Society of Civil Engineers (ASCE), 2018
National Category
Building Technologies Wood Science
Research subject
Technology (byts ev till Engineering), Civil engineering; Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:kau:diva-74371 (URN)10.1061/(ASCE)ST.1943-541X.0002112 (DOI)000441685500001 ()
Available from: 2018-02-12 Created: 2019-08-16 Last updated: 2019-10-23Bibliographically approved
Vessby, J., Enquist, B. & Källsner, B. (2014). Directional dependency in an OSB sheathing-to-framing mechanical connection. In: : . Paper presented at WCTE, World Conference on Timber Engineering, Quebec City, 10-14 August.
Open this publication in new window or tab >>Directional dependency in an OSB sheathing-to-framing mechanical connection
2014 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Nailed connections are commonly employed for connecting sheathings to the framing used in shear walls. Although many aspects of such connections have been investigated thoroughly within the research community generally, the effect the loading direction has on connections of this sort has been much less investigated. In the present study experimental tests were carried out for determining in detail the effects the loading has on different sheathing-to-framing connections. The results obtained indicated the degree of loading to which a nail fastened to an oriented strand board (OSB) sheathing is subjected to not be strongly affected by which of the two main loading directions is involved, but that the effects of loading direction are found to be much greater if the timber element in question is also included in the testing carried out. The dependency of the loading effect on the loading direction at different loading stages and for different directions - parallel to the fibres, perpendicular to them, at some angle between these two main directions - was investigated here.

National Category
Building Technologies
Identifiers
urn:nbn:se:kau:diva-74395 (URN)2-s2.0-84925014934 (Scopus ID)
Conference
WCTE, World Conference on Timber Engineering, Quebec City, 10-14 August
Available from: 2014-05-28 Created: 2019-08-16Bibliographically approved
Serrano, E., Enquist, B. & Vessby, J. (2014). Long term in-situ measurements of displacement, temperature and relative humidity in a multi storey residential CLT building. In: WCTE 2014 - World Conference on Timber Engineering, Proceedings: . Paper presented at World Conference on Timber Engineering, Quebuec City, 10-14 August (pp. 398-405). World Conference on Timber Engineering (WCTE)
Open this publication in new window or tab >>Long term in-situ measurements of displacement, temperature and relative humidity in a multi storey residential CLT building
2014 (English)In: WCTE 2014 - World Conference on Timber Engineering, Proceedings, World Conference on Timber Engineering (WCTE) , 2014, p. 398-405Conference paper, Published paper (Refereed)
Abstract [en]

In a multi-storey residential housing project comprising of four 8-storey timber buildings, the bottom storeybeing designed with concrete and storeys 2-8 in timber, the vertical relative displacement, the temperature and the relativehumidity (RH) along one vertical channel in the external wall of one building has been monitored. Measurements startedduring construction and presented herein are results of 6.5 years of in-situ measurements. Displacement data was monitoredstorey-by-storey, with a sampling frequency of 1 measurement every 10-60 minutes. In another of the four buildingsadditional temperature and relative humidity measurements have been ongoing for about 5.5 years. These temperature andRH measurements were performed at six different locations in the building, at each location in eight positions through theexterior wall with a sampling frequency of 1 measurement every 15 minutes. The results show that the total verticaldisplacement over six storeys after 6.5 years of service life is approximately 23 mm as a yearly average, and over the yearthe displacement varies from this value by approximately ±2 mm. The main cause for the relative displacement is thedecrease of moisture content in the wood material leading to shrinkage after completion of the building. The resultsobtained show also that the exterior wall design of the building behaves well in terms of not comprising a general risk fordamp or mould in the timber core of the external walls.

Place, publisher, year, edition, pages
World Conference on Timber Engineering (WCTE), 2014
Keywords
CLT, long term displacement, relative humidity, temperature, in-situ measurement
National Category
Other Civil Engineering Building Technologies
Identifiers
urn:nbn:se:kau:diva-74389 (URN)2-s2.0-84924957543 (Scopus ID)
Conference
World Conference on Timber Engineering, Quebuec City, 10-14 August
Available from: 2014-05-28 Created: 2019-08-28Bibliographically approved
Vessby, J., Serrano, E. & Enquist, B. (2010). Contact-free measurement and numerical and analytical evaluation of the strain distribution in a wood-FRP lap-joint. Materials and Structures, 43(8), 1085-1095
Open this publication in new window or tab >>Contact-free measurement and numerical and analytical evaluation of the strain distribution in a wood-FRP lap-joint
2010 (English)In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 43, no 8, p. 1085-1095Article in journal (Refereed) Published
Abstract [en]

Wood specimens to each of which alaminate of carbon fibre reinforcement polymers(FRP) was glued (creating a lap joint in each case)were loaded to failure. A total of 15 specimens ofthree types differing in the glued length (anchoragelength) of the FRP laminate (50, 150 and 250 mmrespectively) were tested, their strength, stiffness andstrain distribution being evaluated. Synchronizeddigital cameras (charge-coupled devices) used intesting enabled strain fields on surfaces they weredirected at during the loading procedure to bemeasured. These results were also evaluated bothanalytically on the basis of generalized Volkersentheory and numerically by use of the finite elementmethod. The lap joints showed a high level ofstiffness as compared with mechanical joints. A highdegree of accuracy in the evaluation of stiffness wasachieved through the use of the contact-free evaluationsystem. The load-bearing capacity of joints ofthis type was found to be dependent upon theanchorage length in a non-linear fashion. The experimental,analytical and numerical results were shownto be in close agreement with respect to the strengthand the strain distribution obtained.

Place, publisher, year, edition, pages
Springer, 2010
Keywords
FRP Lap-joint Volkersen Wood
National Category
Building Technologies
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
urn:nbn:se:kau:diva-74403 (URN)10.1617/s11527-009-9568-x (DOI)
Available from: 2019-08-16 Created: 2019-08-16 Last updated: 2019-08-21Bibliographically approved
Serrano, E., Enquist, B. & Vessby, J. (2010). Vertical relative displacements in a medium-rise CLT-building. In: Paulo J.S. Cruz (Ed.), Structures and Architecture: Proceedings of the First International Conference and Architectures, ICSA. Paper presented at Structures and Architecture, Guimaraes, July 2010 (pp. 388-395). Taylor & Francis
Open this publication in new window or tab >>Vertical relative displacements in a medium-rise CLT-building
2010 (English)In: Structures and Architecture: Proceedings of the First International Conference and Architectures, ICSA / [ed] Paulo J.S. Cruz, Taylor & Francis, 2010, p. 388-395Conference paper, Published paper (Refereed)
Abstract [en]

Four buildings with clt-panels in their load bearing structure were built at the block Limnologen in Växjö, Southern Sweden. Their architecture is an example of the new ar-chitecture possible with this building system. Properties of these new structures are sought, one of these being their relative vertical displacement over time. These displacements are measured continuously for six storeys, up to now for just over two years. So far, the total measured dis-placements have reached a maximum of 21.1 mm over the 17.95 meter measuring length. Annu-lar variations of the displacements corresponding to the varying climate may be observed in the data.

Place, publisher, year, edition, pages
Taylor & Francis, 2010
National Category
Building Technologies
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
urn:nbn:se:kau:diva-74390 (URN)10.1201/b10428 (DOI)978-0-415-49249-2 (ISBN)
Conference
Structures and Architecture, Guimaraes, July 2010
Available from: 2019-08-28 Created: 2019-08-28 Last updated: 2019-11-21Bibliographically approved
Vessby, J., Enquist, B., Petersson, H. & Alsmarker, T. (2009). Experimental study of cross-laminated timber wall panels. European Journal of Wood and Wood Products, 67(2), 211-218
Open this publication in new window or tab >>Experimental study of cross-laminated timber wall panels
2009 (English)In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 67, no 2, p. 211-218Article in journal (Refereed) Published
Abstract [en]

The use of cross-laminated structural timber elementsis becoming increasingly popular. The number of layersvaries normally from three upwards. The structural performanceof five-layer cross-laminated timber elements was investigated.The five layers consisted of 19mm thick boards,laid successively at right angles to each other and gluedtogether with PU-adhesive, layers 1, 3 and 5 lying in onedirection and layers 2 and 4 in the other. The stiffness andstrength of four cross-laminated timber elements (4955mmlong, 1250mm wide and 96mm thick) were studied duringin-plane bending. Two of the elements were first partitionedinto two parts that were reconnected in two different waysprior to testing. The influence of the way in which the crosslaminatedtimber elements were reconnected was studied,the behaviour observed being compared with the test resultsfor the unpartitioned specimens with respect to both strengthand stiffness. The experimental tests performed showed thecross-laminated timber elements to possess a high degree ofstiffness and strength. There was also found to be a markeddifference in behaviour between the two different ways inwhich the elements were connected to each other. One of thetwo connecting methods studied, being of less good designbut earlier frequently used in Sweden, showed as expectedpoor structural performance, whereas the other one appliedas a safer alternative performed well.

Place, publisher, year, edition, pages
Springer, 2009
National Category
Building Technologies
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
urn:nbn:se:kau:diva-74396 (URN)10.1007/s00107-009-0313-5 (DOI)
Available from: 2019-08-16 Created: 2019-08-16 Last updated: 2019-08-16Bibliographically approved
Vessby, J., Olsson, A. & Enquist, B. (2008). Contact-free strain measurement of bi-axially loaded sheathing-to-framing connection. In: 10:th World Conference on Timber Engineering: .
Open this publication in new window or tab >>Contact-free strain measurement of bi-axially loaded sheathing-to-framing connection
2008 (English)In: 10:th World Conference on Timber Engineering, 2008Conference paper, Published paper (Refereed)
National Category
Building Technologies
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
urn:nbn:se:kau:diva-74402 (URN)
Available from: 2008-11-11 Created: 2019-08-16Bibliographically approved
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