08.10.2024
We have seen that InfiniSpring® nominal load ranges in the Datasheets for the standard springs are well defined. Springs manage defined nominal loads perfectly and they are not subjected to creep-aging.
We wanted to test InfiniSpring®-springs in overload situations, where load is clearly above the nominal load. We heard from the spring researchers that creep-aging would be fastest during the first three weeks of the testing. After the three week period creep-aging should not be an issue. InfiniSpring® Acoustic Wall Tie 128NN was chosen for the tests. AWT128NN is for nominal loads up to 25 kg.
AWT128NN springs were tested using tensile load. Two springs were overloaded using 30,7 kg and 41,4 kg weights. Initial openings were measured after the loads were applied. For the 30,7 kg weight the initial opening was 7,0 mm and for the 41,4 kg weight 7,9 mm. Initial openings without the loads were 3,9 mm for both springs. Figure 1 shows the spring with tensile overload.
Figure 1. AWT128NN spring overloaded and with a 7,0 mm opening.
Static tensile overload tests started 18.6.2024 and spring openings were measured regularly. Openings remained the same during the tests. After six weeks of testing 1.8.2024 loads were released, and openings were measured to see the plastic deformation magnitude. It can be seen from 1.8.2024 measurement that the initial no load openings have grown slightly from the original: 30,7 kg load from 3,9 mm to 4,2 mm and 41,4 kg load from 3,9 mm to 4,5 mm. This is since the springs are overloaded and yield strength is exceeded in both overload cases. Table 1 below shows all results.
Table 1: Static tensile load test results 18.6.-1.10.2024
Table 1 results show that the openings have remained the same with the overloads. After 1.8.2024 spring 2 was removed and tests were continued for the spring 1 with 30,7 kg load. This test is continued and last check was made 1.10.2024 and spring 1 opening was initial 7,0 mm.
These results indicate that InfiniSpring®-springs can manage static overloads. The spring openings remained the same throughout the testing and no creep-aging was noticed. InfiniSpring®-spring and chosen steel grade seem to perform extremely well even with the static overloads.
