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Glossary of Used Terms and Nomenclature
Used Terms
This is a temporary solution until I will find a more appropriate and interactive one. There are terms within this site, which deserve a more precise explanation, but its useless to repeat it throughout the rest of the text. I am planning to save this glossary to the database, where a click on a chosen term would start a small popup window with a text input from this database. This Glossary page will be then redundant. If you know a good solution for this problem, please let me know.
Before I prepare the new solution, these links will open one new specific Glossary window. Note that if you minimize it or set behind another window, any click to other unknown term will show you new text there, but this necessarily does not mean that the glossary window will get foreground.
Anonymous User: The anonymous user has to fill in the same parameters as the privileged user. Nevertheless, no information, except for his username, will be published or given to other users. He can read data in the database, but he cannot manipulate them within it nor he can add anything new. He does not have access to the user forum. Currently, the only difference to the unknown user (a non-logged visitor) is in availability of PragTic software.
Editing of database items:
Currently the manager is the only user, who can edit any item,
but the expected final state is described in the text further and by revisions:
Privileged users are allowed to edit or add data saved in the databases, but
they do not have any option to delete any item. They can directly edit only the data, that they
manage. If the data are subject to another manager, the concept
of revisions is applied.
Forum: The forum should allow the user of PragTic and the databases here to interact and help one another in search for the right solution. The forum is also intended to give me some overview of desires and problems of the user. You can start it by a click on the Forum button on the right panel, but you are invited in only if you are logged into the system as a privileged user.
Manager: The manager of any item is the privileged user, who created the item in the database. He is responsible for its next development. Until I introduce the idea sketched in the section Concept, if you do not agree with data given by the manager, you have to write about it to the Forum. The manager is the only person (except for administrator Jan Papuga), who can edit the item that he manages. This is not the final state, see the term Edit, where its final idea is sketched.
Notification System:
In order to enhance the usability and efficiency of the data system presented on this website,
the notification system was established. The users can be informed on selected
actions (input of new data, their editing, etc.) occuring on the website by an email automatically generated and
sent to his e-mail box. The setup of personal preferences
can be done after the login either completely in the second part of the
User Profile or on individual webpages concerning any such item
(Conferences, Bugs, etc.).
The system will be subsequently introduced to the website throughout the summer 2008.
Within the completion of the system, I hope, I will be able to enable caching of the
notifications, so that they could be sent together in one e-mail per a period defined by each user.
Privileged User: This category of a user has a permission to add data into the databases. He can ask to get information about changes in the database. He can use the user forum to communicate with the other privileged users. On the other hand, he is asked to disclose a bit more his identity, so that the other users could interact with him. The part data, which the privileged user inputs here are shown on his card in the section Users, except for the e-mail, which is kept secret. This openness should also ensure that the privileged users guarantee for the data they input.
Revision of database items:
This is the last part of the safety measures, which I have not implemented. The only
option today is the direct edit of data, to which you are appointed as the manager.
Except for the common edition of data, to which you have
the managerial competence, you could be tempted to revise
also data of others. Any change from the originally set values is submitted to
approval of its manager. Your proposal does not rewrite the
original data automatically. It is marked as a revision and from its definition a
30-day period starts, in which the manager has to assume some attitude to it. He
gots an automatically generated e-mail with the information about your revision.
In the case the manager does not either reject or approve the change within 30 days,
the change is applied and the managing right and duty descend to the editor.If
the manager and the editor cannot unite their opinions, they should describe the problem
to the Forum.
Sign: Unfortunately, this is another concept that is not currently fully implemented. Thus a future state will be described here. In order to increase credibility of published data, each item in the database can be signed by any of the privileged users. Please, sign the items only in the case, that you personally checked it to the original paper where the data are given or you personally made the computation confirming the results in database.
Nomenclature
&Delta FI: Common calculation methods oriented on evaluation of the loading towards the fatigue limit can be rewritten to a general formula:
,
where the damage parameter Dp is a function of shear C and normal N stress on some particular plane or on more specific planes. The indics a and m are there for amplitude and mean value, while the variable f-1 stands for fatigue limit in a fully reversed axial loading. The inequality mark says that the cases, where the damage parameter is less than the fatigue limit, mark loading, which generates load less than the fatigue limit and thus corresponds to an infinite fatigue life lying behind the fatigue limit.
The right hand side of the inequality above was chosen in order to ensure that it has some physical meaning. Other authors sometimes use other right hand sides, but the clear physics behind this chosen term should be acceptable.
FatLim provides a comparison of validity of calculation methods. All the experimental results gathered correspond to either fatigue limit or some fatigue strength at a definite number of cycles equal or higher to 10^6 cycles. The inequality should become an equality in such a case, but this happens really only rarely. The deviation from the equality shows for the inequality form specified above, how big is the relative deviation from the ideally set multiaxial fatigue limit:
,
and is called the fatigue index error here. As regards the quality of the examined calculation method, the smaller Dp parameter than the fatigue limit means that the loading was analysed non-conservatively - the best available criterion should give results close to zero. A negative number thus marks a non-conservative prediction, a positive number relates to a conservative prediction.
