Applied mechanics

Applied mechanics is a specialized branch of science. It focuses on the motion of substances that humans can perceive without using instruments. While pure mechanics explores theoretical ideas, applied mechanics puts those ideas into practice. It bridges the gap between physical theory and real-world technology. This science is essential for understanding how the physical world functions in everyday life. It connects many different scientific and engineering disciplines through shared research.

To understand how it works, we must look at how forces act on objects. Pure mechanics describes how bodies respond to external forces. These bodies can be solids or fluids. They might be at rest or in motion. Applied mechanics takes these descriptions and applies them to engineering problems. Scientists use theories of classical mechanics and fluid mechanics to solve these problems. This process allows researchers to formulate new ideas and interpret natural phenomena.

Applied mechanics is divided into several distinct branches based on the type of matter. Particle mechanics treats large objects as tiny points called particles. Rigid body mechanics studies objects that have a definite shape and do not deform. Solid mechanics looks at macroscopic solids that can change shape through elastic or plastic deformation. Fluid mechanics focuses on the behavior of macroscopic fluids. Each of these branches is further split into two categories. Statics studies bodies with zero resultant force or torque. Dynamics studies bodies with non-zero resultant force or torque.

Within dynamics, there are two specific ways to study motion. Kinematics is the analysis of moving bodies using time, velocity, displacement, and acceleration. Kinetics is different because it studies motion through the effects of mass and force. In the study of fluids, this is called fluid dynamics. This describes how various fluids flow and move. In statics, researchers look at bodies at rest. They may study non-deformable bodies to analyze forces on rigid structures. They also study deformable bodies to examine material strength.

The history of this science began with Isaac Newton. He published his principles in the book Philosophiæ Naturalis Principia Mathematica in 1687. Later, Franz Josef Gerstner wrote a three-volume work to define applied mechanics as its own discipline. In 1858, William Rankine published the first major English manual on the subject. By 1898, August Föppl introduced calculus to the field. The discipline became truly separate from classical mechanics in the early 1920s. This happened through new journals, societies, and international meetings.

Important figures helped the field grow during the 20th century. Richard von Mises started a major journal in 1921. In 1922, Ludwig Prandtl and von Mises founded the Society of Applied Mathematics and Mechanics. Theodore von Kármán and Tullio Levi-Civita helped organize the first International Congress of Applied Mechanics in 1924. This meeting was held in Delft, the Netherlands, and had over 200 scientists. Stephan Timoshenko emigrated to the U.S. in 1922. He wrote thirteen textbooks and is known as "America's Father of Engineering Mechanics."

Today, applied mechanics is vital across many engineering fields. Civil engineers use it for structural design and earthquake engineering. Mechanical engineers apply it to robotics and nanotechnology. Aerospace engineers use it for aerodynamics and aircraft design. Materials engineers study fracture and failure mechanisms using these principles. Even biomedical engineers use it to model human muscles, tendons, and cartilage. It is a fundamental tool used to develop experimental and computational tools for the future.