# Beams - Fixed at One End and Supported at the Other - Continuous and Point Loads

## Support loads, moments and deflections

### Beam Fixed at One End and Supported at the Other - Single Point Load

#### Bending Moment

MA = - F a b (L + b) / (2 L2)                               (1a)

where

MA = moment at the fixed end (Nm, lbf ft)

F = load (N, lbf)

MF = Rb b                               (1b)

where

MF = moment at point of load F (Nm, lbf ft)

Rb = support load at support B (N, lbf)

#### Deflection

δF = F a2 b2 (3 a + 4 b) / (12 L3 E I)                                  (1c)

where

δF = deflection (m, ft)

E = Modulus of Elasticity (Pa (N/m2), N/mm2, psi)

I = Area Moment of Inertia (m4, mm4, in4)

#### Support Reactions

RA = F b (3 L2 - b2) / (2 L3)                                 (1d)

where

RA = support force in A (N, lbf)

RB = F a2 (b + 2 L ) / (2 L3)                                 (1f)

where

RB = support force in B  (N, lbf)

### Beam Fixed at One End and Supported at the Other - Continuous Load

#### Bending Moment

MA = - q L2 / 8                               (2a)

where

MA = moment at the fixed end (Nm, lbf ft)

q = continuous load (N/m, lbf/ft)

M1 = 9 q L2 / 128                              (2b)

where

M1 = maximum moment at x = 0.625 L  (Nm, lbf ft)

#### Deflection

δmax = q L4 / (185 E I)                                  (2c)

where

δmax = max deflection at x = 0.579 L (m, ft)

δ1/2 = q L4 / (192 E I)                                  (2d)

where

δ1/2 = deflection at x = L / 2   (m, ft)

#### Support Reactions

RA = 5 q L / 8                            (2e)

RB = 3 q L / 8                            (2f)

### Beam Fixed at One End and Supported at the Other - Continuous Declining Load

#### Bending Moment

MA = - q L2 / 15                               (3a)

where

MA = moment at the fixed end (Nm, lbf ft)

q = continuous declining load (N/m, lbf/ft)

M1 = q L2 / 33.6                              (3b)

where

M1 = maximum moment at x = 0.553 L (Nm, lbf ft)

#### Deflection

δmax = q L4 / (419 E I)                                  (3c)

where

δmax = max deflection at x = 0.553 L   (m, ft)

δ1/2 = q L4 / (427 E I)                                  (3d)

where

δ1/2 = deflection at x = L / 2   (m, ft)

#### Support Reactions

RA = 2 q L / 5                            (3e)

RB = q L / 10                            (3f)

### Beam Fixed at One End and Supported at the Other - Moment at Supported End

#### Bending Moment

MA = -MB / 2                               (4a)

where

MA = moment at the fixed end (Nm, lbf ft)

#### Deflection

δmax = MB L2 / (27 E I)                                  (4b)

where

δmax = max deflection at x = 2/3 L   (m, ft)

#### Support Reactions

RA = 3 MB / (2 L)                            (4c)

RB = - 3 MB / (2 L)                       (4d)

## Related Topics

• Mechanics - Forces, acceleration, displacement, vectors, motion, momentum, energy of objects and more
• Beams and Columns - Deflection and stress, moment of inertia, section modulus and technical information of beams and columns
• Statics - Loads - force and torque, beams and columns

## Search the Engineering ToolBox

- "the most efficient way to navigate!"

## Engineering ToolBox - SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your SketchUp model with the Engineering ToolBox - SketchUp Extension/Plugin - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Translate the Engineering ToolBox!
About the Engineering ToolBox!

close