502 tronegpsnmtrstnogpanleo Shear strain(%) that install tion of the ading e possible i testn Pedersen t(999showed oa of similar that n the howa close correlation. Fo al. side 5)This explain.One possible explanation is that rotation in the joint that 6 Re ARAMIS. s in the joint area at N: ring results of the strain distribution in the joint area found by the ARAMIS-system and by numerical analysis system were taken in the elastic rgion just before the joints ndicated Path 1 28 kN fo and 270kN for ent csuobtaincd joints of the ARAMIS-system as ●-Path2 hose of the simulated.The results were not compared in the plastic range since u analyse with elastic behavor 0,60 the with the ARAMIS-system.Due to that 050 s possible 0,40 opposite sid 4.4 Type 1 joints MIS 01020304050607080 esented in Fig.6,which ind X-distance (mm) s close correlation bet en th red and For und at the free end in both cas s.This can be obse more ong a patr inF时 Jorissen(1998)has described the influence of shear stresses are pre cracking ter ADA飞I pendicular to the grain along the line where the final crack later sults showing very similar tendencies.As can be cen in Figs.6 curred were st with these findings in mind.The re sults as the ARA -system at seve MIS502 for type 1 joint, whereas such behavior is observed in the type 2 joint. Hole clearances in the joint area or material defects in the timber are possible explanations for this, but it is also possible that installation of the joints in the wedge device of the loading machine generates this behavior to some extent. The possible in- fluence of eccentricity should not be ignored. In experimental testings, Pedersen et al. (1999) showed eccentricity to affect the load-bearing capacity of similar joints, also finding that increa￾sing the eccentricity produced more brittle behavior. The two measurements systems show a close correlation. For the type 1 joint, the results for both systems being almost identi￾cal, wheras there is a slight deviation of the two for type 2 on the lower side of the joint (Fig. 5). This latter deviation is difficult to explain. One possible explanation is that rotation in the joint area may to some extent generate it if one bears in mind the fact that the two systems do not measure the displacement at exactly the same position. 4.3 Comparing results of the strain distribution in the joint area found by the ARAMIS-system and by numerical analysis The strain distributions in the joint area for the two types of joints are presented below. The results obtained by the ARAMIS￾system were taken in the elastic region just before the joints indicated plastic behavior in the global load-displacement re￾sponse involving a total load of approximately 28 kN for type 1 and 270 kN for type 2 (compare this with the load-displacement results obtained for these two joints of the ARAMIS-system as presented in Figs. 8 and 11). For comparing these results with those of the numerical analyses, the same load levels were then simulated. The results were not compared in the plastic range since the numerical analyses dealt only with elastic behavior. It should be emphasized that only the surface on one side of the joints was studied with the ARAMIS-system. Due to that it is possible that, for example, cracks may have occurred on the opposite side of the joints. 4.4 Type 1 joints The results the ARAMIS-system provided and those of the nu￾merical analyses of the strain distribution in the joint area are presented in Fig. 6, which indicates close correlation between the measured and the theoretical values. For example, large tensile strains perpendicular to the grain can be seen to have developed (red areas) in the area between the dowels and the end-grain sur￾face at the free end in both cases. This can be observed more clearly if the strains along a path extending from the dowel to￾wards the end of the grain surface are plotted as shown in Fig. 7, where strains perpendicular to the grain along two different paths are presented both in terms of the numerical analyses and of the measured values obtained using the ARAMIS-system. There is a rather close correlation, both the measured and theoretical re￾sults showing very similar tendencies. As can be seen in Figs. 6 and 7, some areas close to the dowels and to the end grain cannot be evaluated using the ARAMIS-system. This can be solved by Fig. 6 Results for the strain distributions in the joint area at 28 kN: a numer￾ical results, b results for the ARAMIS-system Abb. 6 Dehnungsverteilung im Verbindungsbereich bei 28 kN: a numerische Ergebnisse, b mit dem ARAMIS-System ermittelte Ergebnisse Fig. 7 Strain distributions perpendicular to the grain along two paths Abb. 7 Dehnungsverteilung senkrecht zur Faser entlang der Linien 1 und 2 studying only a smaller part of the joint although this would be at the expense of missing the overall picture of the strains in the joint area as a whole. Jorissen (1998) has described the influence of shear stresses and tensile stresses perpendicular to the grain on the cracking ten￾dencies of dowel-type joints. The shear strains and strains per￾pendicular to the grain along the line where the final crack later occurred were studied with these findings in mind. The results as obtained by the ARAMIS-system at several different stages are shown in Fig. 8. It can be seen that the tensile strains perpendicu-