Chapter 30: Forensic Engineering

**Forensic engineering**

the application of engineering principles, knowledge, skills, and methodologies to answer questions of fact that may have legal ramifications.

Fire

**D**efined as the rapid oxidation process with the evolution of heat and light.

**self-propagating reaction**

The chemical reaction involved in fire is a **______** that goes on by itself, once started.

heat source

This _____ also leads to the point of origin of fire.

point of origin

This ____ can be found out by finding “the low point”.

low point

This ____ is based on the principle of various rates of propagation of fire in different directions.

rate of propagation

The ______ of fire is maximum in the vertical direction followed by the horizontal direction and least in the downward direction.

differential rate of propagation

This _____ causes fire to move in the form of a “V”.

**Centroid Method**

This method is more useful in cases in which the building is of only one story high and is made of uniform material.

**Warehouse/Box Method**

In this method the damage that fire causes to the walls or the room is used.

**Weighted Centroid Method**

This method assumes that the point that is subject to the longest duration of fire and so is the most severely damaged, is the point of origin of fire.

**Sequential Analysis**

In this method, the point of origin of fire is determined by following in reverse order the trail of fire from where it ends to where it began.

Arson

______ can be defined as the malicious burning of homes, residences, buildings, or other types of real property.

**Primary shorting**

**_______** is that shorting that has started the fire.

**Secondary shorting**

______ is the one that is caused due to fire.

Short circuit

____ causes the electrical conductors to heat up excessively. This causes the insulating material, that is usually made of plastic, to heat up and melt, leaving the conductor bare.

Skid marks

_______ are vital evidence for vehicular accident reconstruction, when their size and shape can reveal much about vehicle speed and forces of acceleration or deceleration.

**skid marks**

The **_____** are produced due to the force of friction acting between the vehicle that is decelerating and the ground.

**Antilock Braking System**

Devised to prevent the tiers from locking when the brakes are applied. They prevent skidding of the vehicle when the brakes are applied suddenly.

**Momentum Method**

This method is based on the principle of conservation of momentum. When two bodies collide, the combined momentum of the system.

**Energy Method**

This method is based on the principle of conservation of energy. When two bodies collide, the combined energy of the system.

**Static loads**

These are the loads of the building itself.

Dead loads

______ are the loads that don’t change with time.

Live loads

______ include those weights that may change with time of the day or season like furniture, machinery, human beings, etc.

**Dynamic loads**

**____** include the loads that change in a very short period of time.

**explosion**

An **_____** is a sudden, violent release of energy. It is usually accompanied by a loud noise and an expanding pressure wave of gas.

**Deflagrating Explosion**

These are the type of explosions in which there is a relatively slow, progressive burn rate of the explosive material.

**Detonating Explosion**

These are the type of explosions in which there is high burn rate, high energy release and a high peak explosion pressure.