huangyhg

fastener load distribution
where may i find a simple shareware computer program that will "accurately" model the load distribution among fasteners common to joints?
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the importance of fastener load distribution depends on the application of the joint. if the joint is to be statically loaded, then an 鈥榓verage鈥?load distribution is satisfactory. the maximum running load of a riveted or bolted lap joint being equal to the number of fasteners multiplied by the joint strength of the fastener multiplied by the number of rows, divided by the pitch. if, on the other hand, the joint is subjected to regular cyclic stress, load distribution becomes very important from a fatigue point of view. this is particularly important under loading conditions in which the fasteners behave as linear elastic
check out the faq, if the post and faq are intersting don't forgrt to vote for them....please.
nigel waterhouse
get your hands on a peery or bruhn aircraft structures textbook, or an advanced mechanics of materials textbook by den hartog or boresi and sidebottom. all of these cover this topic very well. this is a fundamental problem that any aircraft structures engineer worth the title must be able to work out without the finite element method, which can produce very strange results in the hands of an inexperienced analyst, especially one with inadequate training in the theory.
apkohn,
i am not familiar with the reference you quote. could you tell me where i can find it, please. also, i am interested in your problem; sorry i didn't reply to your e-mail. could you give me a few more details regarding the problem.
nigel
nigel waterhouse
regarding locating the esdu data sheets that i quoted, i don't actually know how to get them. we had this particular one in the office. you can find out more about esdu at
the textbook from micheal niu has a relatively easy methods utilizing fem to derive the load distribution of fasteners, but, only contains a limited numbers of fasteners and configurations.
brien (visitor)18 jul 01 22:12
jeffs,
realize it's a little late but i just read your inquiry.
try the website: "design and analysis of mechanically fastened joints and bolted patch repairs" at
in regards to bolted/riveted joints all. go here
can anybody tell me where i can purchase a copy of report no affdl-tr-67-184 "analyitical design methods for aircraft structural joints."
thank you
graham murphy
as of a couple of years ago, you could order one directly from bill mccombs, including his corrections and comments for $19.95 plus $3.00 shipping.
he can be reached at:
w.f. mccombs
2106 siesta dr.
dallas, tx 75224
he also sells a supplement to the bruhn textbook which is worthwhile.
randal heller
thanks superstress.
i have a copy of the bruhn "supplement" and it is a very good addition to the basic text.
fyi i finally purchased a copy of the report from ntis, their no is ad831711.
the report is somewhat dated as it is written pre pc's but there is some interesting data on bolt stiffnesses, and it "filled in some gaps" in my background knowledge.
rgds
graham murphy
graham murphy
from what i have seen, all design of bolted and rivetted joints is based on testthat involve the group and material thicknesses and material properties. analyses is self delusional in that the errors can be so large. stick to standards that are test proven and joint configurations that are test proven.
i am concerned about your statement. for an engineer with 20 years experience it appears to be naive. what is your experience that qualifies you to make such a rash, generalised and demeaning judgment?
nigel waterhouse & associates
aeronautical consulting engineers
transport canada and f.a.a approval of fixed and rotor wing aircraft alterations: structures, systems, powerplants and electrical.
the judgement i make should be taken at face value only- and it is basically a caution against calculating something that has so many influences and variables, including those introduced in manufacture. i base that on design manuals given by a number of aerospace companies, where the joint allowable is the determining factor and invariably it is read from a table that is developed by testing. from my experience, calculations play a part only in shear analysis where the loading on each bolt is calculated using a cg/centroid of bolts method, but the bolt allowable capacity is test derived and is compared to the calculated load to determine the reserve factor.
yakov polyakov, p.e. has a bolt group program that may interest the forum.
to address jeffs's original query, free analysis software capable of joint analysis, you can try a general fe code such as mystran (
some other references:
huth, h., the influence of fastener flexibility ont he predictions of load transfer and fatigue life for multi-row joints," astm conference presentation
tate, m.b. rosenfield, s.j. "preliminary investigation on loads carried by individual bolts in bolted joints," naca tn-1051, washington, 1946.
swift, t., "development of the fail-safe design features of the dc-10," astm stp 486, 1971 pp 164-214.
the were presented in:
muller, r.p.g. "an experimental and analytical investigation on the fatigue behavior of fuselage riveted lap joints", 1995 delft university, p 154.

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