# Maximum Bending Moment

## Simply Supported Beam with Support Added at Midspan to Prevent Excessive Deflection

**Situation**

A simply supported beam has a span of 12 m. The beam carries a total uniformly distributed load of 21.5 kN/m.**1.** To prevent excessive deflection, a support is added at midspan. Calculate the resulting moment (kN·m) at the added support.

A. 64.5 | C. 258.0 |

B. 96.8 | D. 86.0 |

**2.** Calculate the resulting maximum positive moment (kN·m) when a support is added at midspan.

A. 96.75 | C. 108.84 |

B. 54.42 | D. 77.40 |

**3.** Calculate the reaction (kN) at the added support.

A. 48.38 | C. 161.2 |

B. 96.75 | D. 80.62 |

## Solution to Problem 457 | Moving Loads

## Solution to Problem 456 | Moving Loads

**Problem 456**

Three wheel loads roll as a unit across a 44-ft span. The loads are P_{1} = 4000 lb and P_{2} = 8000 lb separated by 9 ft, and P_{3} = 6000 lb at 18 ft from P_{2}. Determine the maximum moment and maximum shear in the simply supported span.

## Solution to Problem 455 | Moving Loads

**Problem 455**

A tractor weighing 3000 lb, with a wheel base of 9 ft, carries 1800 lb of its load on the rear wheels. Compute the maximum moment and maximum shear when crossing a 14 ft-span.

## Solution to Problem 454 | Moving Loads

**Problem 454**

Repeat Prob. 453 using axle loads of 30 kN and 50 kN on a wheel base of 4 m crossing an 8-m span.

## Solution to Problem 453 | Moving Loads

**Problem 453**

A truck with axle loads of 40 kN and 60 kN on a wheel base of 5 m rolls across a 10-m span. Compute the maximum bending moment and the maximum shearing force.