This paper reports the experimental results of a study investigating the effect of adhesive joint end shapes on the load-bearing capacity of carbon fibre-reinforce polymer (CFRP) and steel bonded joints. In the study, samples with new proprietary types of CFRP strip ends were examined. All samples were subjected to tensile quasi-static loading with a load rate of 1.5 mm/min. A total of 60 samples with CFRP/steel single overlap joints were tested to determine their ultimate load-bearing capacity, effective bond length and failure modes for the above variables. 8 joint end shapes of normal CFRP modulus with three lengths of CFRP overlap and one CFRP cross section (20 x 1.4 mm) were used in this study. Laboratory test results showed that joint end shape has visible effect on the load capacity of the CFRP/steel bonded joints. The load-bearing capacity of the samples with a regular joint end was up to 28 % lower than that of the samples with a plan-shaped end and 30 % lower than that of the samples with a chamfered end with adhesive outflow. The differences in the results decreased with increase in joint end length towards the effective end length.
The article presents the possibility of using twin-spot laser welding (i.e. laser welding with focusing a laser beam on two spots) for making overlap joints made of 0.8-1 mm thick HSLA and DP type high strength steel sheets. Joints were made using a Yb:YAG disc laser having a maximum power of 12 kW and a welding head by means of which it was possible to focus a laser beam on two spots, 0.6 mm and 1 mm away. The angle between focuses amounted to 0° or 90°, whereas the power distribution was 50%-50%. With settings as presented above it was possible to obtain high-quality overlap joints. The geometrical parameters of the joints were primarily affected by beams positions (in relation to each other) and, to a lesser degree, by the distance between the focuses. It was possible to obtain a 10% hardness reduction in the fusion zone of the DPHSLA steel joints if the angle between the beams amounted to 90°. The tests also involved microstructural examinations of individual zones of the joints.
In calculating the resistance of welds within the connections between hollow sections in EN 1993-1-8, very general information is given without presenting specific calculations. The chief recommendations indicate that the resistance of the welds connecting the wall to the second element should not be less than the resistance of the cross section of the wall. In addition, assessment of the welds’ resistance based on the effective lengths is viable in cases when forces in the braces are smaller than the resistance of the joint, though the detailed method was not specified. The objective of this paper is to present the most up-to-date information about the design of overlap welded joints with a reinforcing rib plate.
These joints are used when the designer and contractor anticipate difficulties during the construction of overlap joints. They were not included in the PN EN 1993-1-8 in full scale. Resistance assessment of such joints is presented in accordance with standard rules. The results were compared with the experimental studies carried out at the “Mostostal” Centre; while the former research activities and the legitimacy of the proposed method of assessing the resistance of these joints was confirmed. This is an example of an overlap joint calculation.
5
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The fatigue tests results of overlap and fronted glue joints are showed in the article. Moreover an influence of adhesion on fatigue life of glue joints were also evaluated. The joints were made with the Epidian 57 and regenerative composites which can be used in emergency repairs of different equipment.
6
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Przedstawiono zalety i wady wybranych metod spawania i zgrzewania punktowego złączy zakładkowych cienkich blach. Określono parametry spawania punktowego metodą TIG i metodą plazmową blach ze stopu tytanu AMS 4928Q. Porównano wyniki prób wytrzymałościowych złączy zakładkowych wykonanych metodą spawania punktowego TIG i metodą plazmową oraz zgrzewania rezystancyjnego punktowego.
EN
Advantages and drawbacks of selected spot welding methods for the manufacture of overlap joints in thin sheets are presented. The parameters of TIG and plasma spot welding of AMS 4928Q titanium alloy sheets have been determined. The results of mechanical testing of overlap joints welded by TIG, plasma and resistance spot welding method have been compared.
8
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Opisano wyniki badań wpływu parametrów procesu automatycznego spawania punktowego metodą GTA, bez materiału dodatkowego, na jakość, kształt oraz właściwości mechaniczne złączy zakładkowych blach ze stali austenitycznej AISI 321 o grubości 1,0 mm oraz określono optymalne warunki technologiczne spawania tych złączy.
EN
It has been described the results of investigations into the influence of automatic autogenous GTA spot welding parameters on the quality, shape and mechanical properties of overlap joints in 1,0 mm thick AISI 321 austenitic steel sheets as well as it has been determined the optimum technological conditions for welding of such joints.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.