Spring Life?
07-28-2009, 11:16 PM
#1
Melting Slicks
Thread Starter
Spring Life?
Guys,
Do the composite Z06 GM transverse leaf springs or the T1 springs cycle out and loose their spring rate or just degrade from the elements?
Do the composite Z06 GM transverse leaf springs or the T1 springs cycle out and loose their spring rate or just degrade from the elements?
07-29-2009, 10:06 AM
#3
Race Director
I know of several rear "failure", usually due to improper exhaust routing or lack of protection. I can't imagine the stiffness of a composite spring changing greatly without visibly delaminating/cracking. They may settle slightly, but I wouldn't expect the rate to change much. Just my opinion
07-29-2009, 10:25 AM
#4
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Yes, you would not think so, but composites do fatigue. I brought this up on F-22 and no one thought it was an issue until I got my hands on some data on the subject. There is micro cracking in the matrix and fibers that eventually start adding up.
07-29-2009, 12:03 PM
#6
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EDIT:
Here's a good book on the subject
http://www.woodheadpublishing.com/en/book.aspx?bookID=3
his major handbook is the first authoritative survey of the current understanding of fatigue behaviour in composites. It deals in detail with a wide range of problems met by designers in the aerospace, marine and structural engineering industries.
Fibre composites, like metals, exhibit a form of degradation in service which may be described as 'fatigue'. The mechanisms by which this deterioration occurs in composites are quite different from, and much more complicated than, those which are responsible for fatigue phenomena in metals, but the problems facing the designer are similar. The challenge for the engineer is to specify materials and use them in such a way as to avoid failures within the design life of a component or structure.
It is of paramount importance for engineers to understand fatigue in composites because it can be a causative agent in design failures some of which – for example in aircraft, can be catastrophic. By increasing their knowledge and awareness of the mechanisms that result in degradation during service, and developing the ability to predict the life of a given composite under specified conditions, engineers will be able to produce materials with more desirable characteristics.
The aim of this handbook is to provide the first wide-ranging account of current research, from internationally recognised authors, into all aspects of this increasingly important field.
The book is divided into four main parts.
Part 1 gives a general introduction to fatigue in composites, providing background information on basic mechanics and analysis.
Part 2 is a more focussed review of current research on micromechanical aspects.
Part 3 gives analysis of various types of composites with respect to fatigue behaviour and testing are then duly treated.
Part 4 An in-depth coverage of life-prediction models for constant and variable stresses is then presented.
The final chapters give an overview of the wider range of problems met by designers in aerospace, marine, and structural engineering.
Compiled from contributions of some of the most eminent researchers in the field, it provides an invaluable, practical and encyclopaedic handbook for designers as well as an authoritative reference source for materials scientists.
Fibre composites, like metals, exhibit a form of degradation in service which may be described as 'fatigue'. The mechanisms by which this deterioration occurs in composites are quite different from, and much more complicated than, those which are responsible for fatigue phenomena in metals, but the problems facing the designer are similar. The challenge for the engineer is to specify materials and use them in such a way as to avoid failures within the design life of a component or structure.
It is of paramount importance for engineers to understand fatigue in composites because it can be a causative agent in design failures some of which – for example in aircraft, can be catastrophic. By increasing their knowledge and awareness of the mechanisms that result in degradation during service, and developing the ability to predict the life of a given composite under specified conditions, engineers will be able to produce materials with more desirable characteristics.
The aim of this handbook is to provide the first wide-ranging account of current research, from internationally recognised authors, into all aspects of this increasingly important field.
The book is divided into four main parts.
Part 1 gives a general introduction to fatigue in composites, providing background information on basic mechanics and analysis.
Part 2 is a more focussed review of current research on micromechanical aspects.
Part 3 gives analysis of various types of composites with respect to fatigue behaviour and testing are then duly treated.
Part 4 An in-depth coverage of life-prediction models for constant and variable stresses is then presented.
The final chapters give an overview of the wider range of problems met by designers in aerospace, marine, and structural engineering.
Compiled from contributions of some of the most eminent researchers in the field, it provides an invaluable, practical and encyclopaedic handbook for designers as well as an authoritative reference source for materials scientists.
Last edited by BrianCunningham; 07-29-2009 at 12:07 PM.
07-29-2009, 11:19 PM
#7
Melting Slicks
Thread Starter
I suspect the springs would fatigue but don't know their duty life. Does anyone know if T1 racers have routinely replaced to new T1 springs and noted any changes? Anyone care to guess at T1 spring life? 4 seasons? 2 seasons? My guess is that no one ever changes them.
07-30-2009, 01:55 PM
#8
Race Director
According to this article they last a long time.
07-30-2009, 06:53 PM
#9
Melting Slicks
Thread Starter
Very interesting article ardwolf. I find the idea of deleting sway bars as interesting. With that in mind I am amazed by the giant T1 sways especially after GM already made a stiffer T1 spring. I see many really nicely done C5Z's with coilover suspension and adjustable shocks. I also notice that compared to my T1 brothers they are not faster on track. I do not see enough CO cars racing to make a scientific statement but it sure seems like the T1 guys have the lowest laptimes. How much is skill vs. car I do not know.
