Design Shear Stress Solution - UCFileSpace Tools -...

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DESIGN FOR SHEAR STRESS 1 τ= P S A Guideline for design shear stress τ d based on yield strength in shear S ys or ultimate strength in shear S us 1. Recognize 6000psi 2. Identify P 3. Visualize shear plane dimensions 4. Substitute into equation τ d = P S A 1.Use guideline and material property to find τ d 2. Visualize shear plane 3. Write equation τ d =S us = P S A Solve for τ d given = 6000 psi P S given = 21000 lb (8 inches) x (a inches) τ d = P S A S 6000 lb ¿ 2 = 21000 lb ¿¿ a = 0.438 in τ d = S US = (448 N/mm 2 ) (0.82) (circumference) Χ P S = (circumference)x(thickness) = τ d = P S A S

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Page 1: Design Shear Stress Solution - UCFileSpace Tools - …homepages.uc.edu/.../Courses/MMI/DesignShearStress_sol.docx · Web viewHW#12 Author lcaldwell Created Date 08/31/2007 06:15:00

DESIGN FOR SHEAR STRESS 1

τ=PSAS

Guideline for design shear stress τd based on yield strength in shear Sys or ultimate strength in shear Sus

1. Recognize 6000psi as τd

2. Identify PS

3. Visualize shear plane dimensions

4. Substitute into equation τ d=PSAS

and solve for a

1.Use guideline and material property to find τd

Force must cause material to fail.

2. Visualize shear plane and find AS

3. Write equation τ d=Sus=PSAS

Solve for force PS

τd given = 6000 psi

PS given = 21000 lb

(8 inches) x (a inches)

τ d=PSAS

6000 lb¿2 =

21000 lb¿¿

a = 0.438 in

τd = SUS = (448 N/mm2)(0.82)

(circumference) Χ PS = (circumference)x(thickness) = π∙ d∙ t

τ d=PSAS

(0.82)(448 Nmm2 )=

PSπ (20mm )(8mm)

PS = 184700 N = 184.7 kN

Page 2: Design Shear Stress Solution - UCFileSpace Tools - …homepages.uc.edu/.../Courses/MMI/DesignShearStress_sol.docx · Web viewHW#12 Author lcaldwell Created Date 08/31/2007 06:15:00

40mm

AyAs

F2

3.6kN

30o

10o

DESIGN FOR SHEAR STRESS 2

1. Draw free-body diagram

2. ΣFx = 0 ΣFy =0 ΣM=0 (three equation, 3 unknowns)

3. Solve for Ax Ay and A

4. Find Guideline for τd 5. Find material property, Sus or Sys

6. Find smallest possible pin diameter to be safe

HW#12

∑ F x=0=F2 ( cos10o )+Ax+3.6kN (cos30o)∑ F y=0=F2 (sin 10o )+A y−3.6 kN (sin 30o)

∑M F2=0=−Ax (25mm )+A y (10mm )−3.6kN ( cos30o ) (55mm )−3.6kN (sin 30o )(50mm)

A x=10.24kNA y=0.544 kNA=√(10.25kN )2+(0.544 kN )2=10.26 kN

τ d=S y8

Sy = 1000 N/mm2

τ d=PSAS

1000 Nmm2

8=10.26×103N

π d2

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Page 3: Design Shear Stress Solution - UCFileSpace Tools - …homepages.uc.edu/.../Courses/MMI/DesignShearStress_sol.docx · Web viewHW#12 Author lcaldwell Created Date 08/31/2007 06:15:00

DESIGN FOR SHEAR STRESS 3