Nothing varies like the lifespan does
The lifespan of springs is something that nobody in the market, the spring manufacturer in particular, would stick his neck out for. The challenge is to keep on trying to achieve something in this area. When it comes to door springs (sectional, tilting, industrial or simply a garage door, it becomes easier. After all we have tonnes of testing data at our disposal. For these springs, drawing up a material and calculation specification, in connection with the lifespan, is easier.
Of course this remains purely theoretical, because in practice there are many variables. This was reason enough for us to start organising a brand new test centre, early 2018, and invest even more in Research & Development. In the new R&D centre, testing takes place continuously, mostly in cooperation with market relations. Who would be more aware of the load specifications than the end user?
The example of the trampoline
Still, in many cases it is a matter of conjecture. An obvious example are trampoline springs. How exactly are the springs burdened? What risk lies in the fact that the springs may fail? In short, what is the actual desired lifespan? In case of trampoline springs with loop ends, one shouldn’t exceed 10,000 cycles (quasi static, because the loop end will always be the weak spot), but in practice that means perhaps only a week of jumping. Fortunately in these cases, we consult our partner to be able to adjust the design in order to tackle these kinds of problems.
Of course, the question remains “how exactly are trampoline springs burdened”, for which there is no simple answer, so with regard to this, together with our partner, we perform a lot of fieldwork, data analysis and factually a complete DFMEA (Design Failure Mode Effect Analyses). “Learning by doing” as the saying goes and that applies to R&D in particular.
Did you miss previous episodes of the research & development series? Read part 3 here!
By: Marco Dekker | Head of research & development