Rate-of-Load and Duration-of-Load Effects for Wood Fasteners
Publication: Journal of Structural Engineering
Volume 125, Issue 7
Abstract
It has been suggested that duration-of-load (DOL) effects in connections differ substantially from those in wood members and that the factors developed using cumulative damage models based on tests of wood members in bending (i.e., creep rupture) are not appropriate for the design of connections. This paper presents the results from a test program that attempts to quantify rate-of-load and short-term DOL effects for wood fasteners (such as nails and screws) subject to withdrawal or lateral loads. The results from this preliminary study suggest that no obvious rate-of-loading effects exists for nailed connections subject to either lateral or withdrawal loading. This has particular significance, for example, in the design of roof sheathing systems and roof-to-wall connections to resist high-wind uplift loads. Although by no means a complete treatment of the topic of DOL (i.e., time) effects in fasteners, this study serves to highlight differences between connection and wood member time effects and both raises and answers some questions about the validity of adjustment factors for time effects for short-term loadings (i.e., wind and seismic) in wood connection design.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Barrett, J. D., and Foschi, R. O. ( 1978a). “Duration of load and probability of failure in wood. Part I: Modelling creep rupture.” Can. J. Civ. Engrg., Ottawa, 5(4), 505–514.
2.
Barrett, J. D., and Foschi, R. O. ( 1978b). “Duration of load and probability of failure in wood. Part II: Constant, ramp, and cyclic loadings.” Can. J. Civ. Engrg., Ottawa, 5(4), 515–532.
3.
Ellingwood, B., and Rosowsky, D. V. (1991). “Duration of load effects in LRFD for wood construction.”J. Struct. Engrg., ASCE, 117(2), 584–599.
4.
Foschi, R. O., and Barrett, J. D. (1982). “Load-duration effects in western hemlock lumber.”J. Struct. Div., ASCE, 108(7), 1494–1510.
5.
Foschi, R. O., Folz, B. R., and Yao, F. Z. ( 1989). “Reliability-based design of wood structures.” Struct. Res. Ser., Rep. No. 34, Dept. of Civ. Engrg., University of British Columbia, Vancouver.
6.
Foschi, R. O., and Yao, Z. C. ( 1986). “Another look at three duration of load models.” Proc., 17th IUFRO Congr.
7.
Fridley, K. J., Tang, R. C., Soltis, L. A., and Yoo, C. H. (1992a). “Hygrothermal effects on the load-duration behavior of structural lumber.”J. Struct. Engrg., ASCE, 118(4), 1023–1038.
8.
Fridley, K. J., Tang, R. C., and Soltis, L. A. (1992b). “Load-duration effects in structural lumber: Strain energy approach.”J. Struct. Engrg., ASCE, 118(7), 2351–2369.
9.
Gerhards, C. C. ( 1979). “Time-related effects on wood strength: A linear cumulative damage theory.” Wood Sci., 11(3), 139–144.
10.
Gerhards, C. C. ( 1988). “Effect of grade on load-duration of Douglas-fir in bending.” Wood and Fiber Sci., 20(1), 146–161.
11.
Gerhards, C. C., and Link, C. L. ( 1987). “A cumulative damage model to predict load duration characteristics of lumber.” Wood and Fiber Sci., 19(2), 147–164.
12.
Johns, K., and Madsen, B. ( 1982). “Duration of load in lumber. Part I: A fracture mechanics approach.” Can. J. Civ. Engrg., Ottawa, 9(4), 502–514.
13.
Kallem, M. R. ( 1997). “Roof sheathing attachment for high wind regions: Comparison of screws and nails,” MS thesis, Dept. of Civ. Engrg., Clemson University, Clemson, S.C.
14.
Karacabeyli, E. ( 1988). “Duration of load research in North America.” Proc., 1988 Int. Conf. on Timber Engrg., R. Y. Itani, ed., Vol. 1, Forest Products Research Society, Madison, Wis., 380–389.
15.
Madsen, B. ( 1973). “Duration of load tests for dry lumber in bending.” Forest Products J., 23(2), 33–40.
16.
Madsen, B., and Johns, K. ( 1982). “Duration of load effects in lumber. Part II: Experimental data.” Can. J. Civ. Engrg., Ottawa, 9, 515–525.
17.
Manual for engineered wood construction—load and resistance factor design (LFRD). (1996). American Forest and Paper Association, Washington, D.C.
18.
Miner, M. A. ( 1945). “Cumulative damage in fatigue.” J. Appl. Mech., 12(3), A159–A164.
19.
National design specification for wood construction. (1991). American Forest and Paper Association, Washington, D.C.
20.
Nielsen, L. F., and Kousholt, K. ( 1980). “Stress-strength-lifetime relationship for wood.” Wood Sci., 12(3), 162–174.
21.
Philpot, T. A. ( 1992). “The effect of creep on the performance and reliability of wood structures,” PhD dissertation, School of Civ. Engrg., Purdue University, West Lafayette, Ind.
22.
Rosowsky, D. ( 1992). “A static-fatigue damage accumulation model for wood connections subject to cyclic loads.” Struct. Engrg. Rep. No. CE-STR-92-9, Purdue University, West Lafayette, Ind.
23.
Rosowsky, D., and Ellingwood, B. ( 1990). “Stochastic damage accumulation and probabilistic codified design for wood.” Civ. Engrg. Rep. No. 1990-02-02, Johns Hopkins University, Baltimore, Md.
24.
Rosowsky, D., and Ellingwood, B. (1991). “System reliability and load sharing effects in light frame wood construction.”J. Struct. Engrg., ASCE, 117(4), 1096–1114.
25.
Rosowsky, D., and Fridley, K. ( 1992). “Stochastic damage accumulation and reliability of wood members.” Wood and Fiber Sci., 24(4), 401–412.
26.
Rosowsky, D. V., and Fridley, K. J. ( 1995). “Directions for duration-of-load research.” Forest Products J., 45(3), 85–88.
27.
“Standard test methods for mechanical fasteners in wood.” (1992). D1761-88, ASTM, West Conshohocken, Pa.
28.
Wood, L. W. ( 1951). “Relation of strength of wood to duration of load.” Rep. No. 1916, USDA Forest Service, Forest Products Laboratory, Madison, Wis.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 125 • Issue 7 • July 1999
Pages: 719 - 724
History
Received: Oct 14, 1998
Published online: Jul 1, 1999
Published in print: Jul 1999
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.