CALCS PROC013
PIN PLATES 160404

CONTENTS

INTRODUCTION
NOTATION
INPUT TO PROCEDURE
OUTPUT FROM PROCEDURE
PROJECT EXAMPLE INPUT
PROJECT EXAMPLE OUTPUT

INTRODUCTION


Pin plate loaded by transverse force applied by pin. Found in many structures and most mechanisms. Due consideration should be taken for the case of very thick lugs in that a uniform through thickness stress distribution is not valid.

SEE ALSO: PROC012 PROC017 PROC025

THEORETICAL BASIS: Roark5 T16 I1, DNV CN 2.7-1 & AISC 360-10 Sec.D5. To account for the variation in tensile stress across the lug, a thick cylinder analogy is used for the pin bearing stress in the hole.

theory_doc

NOTATION


fbrstress-bearing, on diameter D
ftstress-tensile,lug
fsstress-shear,lug
Nk%Code for acceptance criteria
PTransverse force acting between pin & plate
RdDoubler plate thickness
RiPin hole radius
RoPlate outer radius
RpPin radius
TmMain plate thickness
TdDoubler plate thickness
TwWeld thickness fixing doublers to main plate

INPUT TO PROCEDURE


1st Principles analysis (1Pr) is used by default.

Radial Strain analysis (RStrain) calculates pin plate (in-plane) bending stress with account of the difference between pin & hole radii. Plate bending increases with this difference and is normally neglected in the design standaords. This bending is significant only for pin plates requiring special levels of design assurance.

Choose compliance standard from AISC and/or DNV, as appropriate for the project.

Inclusion of doubler plates in the design of pin plates is not unusual. However, the thickness (Td) being included in the analysis needs to done with caution. This is mainly because the welds fixingthe doublers are not always adequate for the full pr oportion of load carried by them. They are known to be included in some designs to increase bearing area and hence limit pressure for some bearings (in which the pin may rotate) fitted to the plates.

OUTPUT FROM PROCEDURE


The 1st Principles plate tension stress (ft) is actually non-conservative but used in some design standards with a high safety factor. The diameter of a pin will normally be less than that of the pin hole. The minimum possible bearing width (between pin & hole) will be limited by bearing stress. For this reason, the bearing utilisation is based on yield and is always equal to unity.

DNV use a constant (conservative) stress magnification factor (3.0) for tension stress to account for the stress varying effects of the plate width, pin diameter & hole diamenter.

Notice that AISC has dimensional requirements to be met.

PROJECT EXAMPLE INPUT


PROCtitle("MB -1030103 PT1","MB Heel","L07")
section$=" 1Pr AISC "
LET Nm%=steel:Ngr%=S355:Nk%=AISC:Ro=25:Ri=20/2:Rp=.98*Ri:Rd=0:Tm=6:Td=0:Tw=0:P=L07/2
PROC013



PROJECT EXAMPLE OUTPUT


MB - PROC013 Eyeplate Strength 130809 - MB Heel


a) 1st Pr. - Strength of Eyeplate with Two Doubler Plates,

MB - PROC013 a) 1st Pr. - MB Heel


Tension & Shear Across Eye,
LET T=Tm+2*Td:Pm=P*(Tm/T):Pd=P*(Td/T)
LET T=6:Pm=244.3:Pd=0
ft= P/(2*Tm*(Ro-Ri)+2*2*Td*(Rd-Ri))= 1.357
UF_001= ft/(dac(Nk%,Kd%)*mgr(Ngr%,Fy%))= 0.6372
fs= Pm/(2*T*(.5*(SQR(4*Ro^2-(2*Ri*COS(RAD(45)))^2)-2*Ri*COS(RAD(45)))))= 1.204
UF_002= fs/(dac(Nk%,Ks%)*mgr(Ngr%,Fy%))= 0.8479
Min contact angle limited by bearing,
theta_br= ASN(P/(2*Rp*Tm*mgr(Ngr%,Fy%)))= 0.6251
theta= theta_br= 0.6251
Stress (bearing) contact between eye & pin,
fbr1= P/(2*SIN(theta)*Rp*Tm)= 3.55
UF_003= fbr1/(dac(Nk%,Kbr%)*mgr(Ngr%,Fy%))= 1
Curved Beam Parameters
LET c=(Ro-Ri)/2:R=(Ro+Ri)/2
LET c=7.5:R=17.5
h= c*(R/c-2/LN((R/c+1)/(R/c-1)))= 1.13
Rna= R-h= 16.37
I= Tm*(Ro-Ri)^3/12= 1687
d) AISC 360-10 D5 Pin Plate Strength & Dimensional Requirements,
where be based on cm dims

MB - PROC013 d) AISC Tension -


be= 2*Tm+1.6= 13.6
Pn= mgr(Ngr%,Ftu%)*2*Tm*be= 799.7
UF_004= P*2/Pn= 0.611

MB - PROC013 d) AISC Shear -


Asf= 2*Tm*(Ro-Ri+Rp)= 297.6
Pn= .6*mgr(Ngr%,Ftu%)*Asf= 874.9
UF_005= P*2/Pn= 0.5584

MB - PROC013 d) AISC Dims -


UF_006= 2*Ri/(2*Rp+.1)= 1.0151.015
UF_007= (2*be+2*Rp)/(2*Ro)= 0.936
UF_008= 1.33*be/Ro= 0.7235
END013

PROJECT END