# Introduction to Engineering Mechanics

## An Introduction to Engineering Mechanics: Integrating Theory into Practice

Engineering mechanics is understood by many to be the application of mechanics to solve problems. Yet, for engineers, this definition is a bit vague, as it overlooks key questions like: What is being applied? And how exactly are these constitutions working together?

To answer such questions, one must first examine the fundamentals of engineering mechanics, and then see how these fundamentals work together to solve engineering problems.

Forces, torques and dynamics will be some of the defined fundamentals, but before the explaining begins, the importance of obtaining a holistic understanding both of the elements and their interactions should first be noted. The rationale for obtaining a holistic understanding is that civil engineers will not only be expected to solve problems, but will also need to explain how problems are, or could be, solved.

Most of the time engineers will be explaining to individuals who don’t have a firm grasp on the engineering vernacular. Therefore, for clear communication, it will often be necessary to translate engineering knowledge into something more consumable for the general public.

Engineers who possess fundamental knowledge of engineering mechanics will stand apart from their colleagues, as they will be able to swiftly flow from analyzing with other engineers to explaining potential problems to those not mechanically savvy.

## Back to Basics: The Fundamentals of Engineering Mechanics

A **Force** is defined as an application of pressure either geared toward or pulling away from an object. The exertion of this force always involves an external – i.e. outside, different – object or source, such as gravity or magnetism.

Mathematically speaking, a force is considered to be an object’s mass multiplied by its acceleration (F = m • a). It should be noted though, that all objects, even those that don’t appear to be moving, have forces acting upon them. Thus, the power and direction of a force determines that of a moving object, whereas it is the counter-force that determines the power and direction of a static object.

Keeping forces in mind, we will next examine **torque**, which is understood to be the rotational counterpart of a force, and is produced via the application of one or more forces. In particular, torque is often relative to a previously determined pivot or rotational axis.

The fundamentals of torque are predominately dependent upon the force(s) it interacts with. For example, torque is directly influenced by the magnitude of the force, as well as how far the applied force is from the rotation axis. Some real world examples of torque would include the motion of a golf swing or the rotating blades of a lawn mower.

**Statics** are understood as a branch of mechanics that analyze the torques and forces acting upon resting bodies. For engineers, these resting bodies are commonly referred to as rigid bodies (a body upon which there is a constant, never-changing distance between two points, no matter the force applied on it).

With rigid bodies comes what engineers describe as static equilibrium. In particular with statics, engineers are interested in studying the effects and distribution of torques and forces upon this equilibrium.

**Dynamics** also relate to torques and forces, but this branch of engineering is particularly interested in the impact that torques and forces have on motion. Thus, dynamics could be properly described as the vector of engineering mechanics that study bodies in motion.

The branch of dynamics is segmented into two fundamental parts: kinematics and kinetics. Kinematics involves motion, be it that of a particle or body, yet this particular segment of dynamics is not at all concerned with the forces behind the motion. Conversely, kinetics is concerned with the acting force.

## Interaction of Engineering Mechanics

As you may have observed, there are numerous interactions between the fundamentals of engineering mechanics, so much so that their relationship could be best described as symbiotic.

For example, without torques or forces there cannot be dynamics. Or even further, without a force there cannot be a torque. Therefore, it is often helpful to take a holistic approach to understanding by thinking of mechanics as a team of interrelated elements.

Like a team, each element has an individual quality but is relatively limited in what it can provide if left to its own devices. But when an element interacts with other elements (i.e. team members), it can accomplish and create far more than it could on its own.

Such symbiotic interaction also extends to the relationship that engineers will have within their respective company. Engineers will often be the force propelling a company’s product, making it critical for an engineer to understand the company’s initiatives in order to steer the company in the right direction.

Considering this, those that become masters of holistic understanding will separate themselves two-fold: 1) they will be able to clearly articulate engineering concerns or solutions; and 2) they will be able to translate innovative dreams into mechanical realities, thus continuing to create and expand future innovations.

**Resources:**

Library Articles Torque

Mechanical Engineers

Mechanics Engineering Field

Engineering Mechanics Statics

–

December 2015