Fatal consequences of construction errors
The consequences of severe construction errors ruin many companies.
A rule of thumb says that the costs increase by a factor of 10 every time a change of building components at different development stages (planning, production, testing, customer usage) is required.
However, really expensive damage events only happen with your customers.
Therefore, it is even more surprising that the same errors with the damage analyses in the construction and development departments are repeatedly made. If you know these, you can try to avoid them as early as in the development of the building components and the assembly.
In this context, errors are not only broken building components but also if these parts no longer meet the agreed properties, either immediately or in the course of time.
Damage analyses have always been my hobbyhorse – to find out what the causes are if the building components do not do what the developing engineers intended them to do.
I made an amazing discovery: In none of the several hundred cases in more than 26 years of my professional career was the cause an unfortunate set of circumstances, such as
- bad material
- slightly higher charges
- poorly done weld seams
- too large tolerances
However, these did play a role and were the straw to break the camel’s back.
But as a rule, there was a single major cause!
And this major cause was a construction mistake that should have been recognized as such.
These errors occur repeatedly and can be divided into a few groups.
In future blogs and special webinars, I will go into single construction errors that I have experienced over and over.
Error #1: Misplacement of ribs
With the ribbing of building components, the ribs should be stressed on tension and compression, not on bending.
Incorrect and correct ribbing
The opposite figure shows what could go wrong:
In the left figure, the ribs do not go to common nodal points. The ribs end on other ribs and, therefore, stress the bending.
If the ribs are misplaced, the impact on the stiffness is lower in the places where the flow of force is interrupted or diverted, and an unnecessary high stress occurs due to the bending.
Stress concentrations cause cracks to emanate from these places.
If the basic principle is understood, you will quickly see that these considerations can be transferred to machine frames, frame constructions, etc., as well.
Conclusion: Wrong or poor ribbing are no use and fail faster.
I am looking forward to your questions.
➞ Read part 2 of this article