Final answer:
To determine the internal forces at a point in a beam, one must analyze static equilibrium using a free-body diagram and apply the conditions of equilibrium to solve for unknown forces and moments.
Step-by-step explanation:
To determine the internal normal force, shear force, and bending moment at point C of a beam, an understanding of static equilibrium and structural analysis is required.
The process involves creating a free-body diagram of the beam and applying the conditions of equilibrium: the sum of horizontal forces must be zero, the sum of vertical forces must be zero, and the sum of moments about any point must also be zero. By systematically applying these conditions, it is possible to solve for the unknown forces and moments on the beam, including the location at point C.
Typically, this would involve resolving the forces at the supports or into their components, setting up equations for force and moment equilibria, and solving those equations. This might be complicated by distributed loads, multiple supports, and various types of loading (point, distributed, or moment loads).
In cases where weight distribution and other forces (such as torque) come into play, these also need to be taken into account to accurately calculate the forces and moments at a specific point.
If the weight is evenly distributed, as in the problem statement concerning door ('Ay = By'), this simplifies the calculations somewhat. For materials under load, the shear modulus (S) is a significant property that relates to the material's response to shear stress, determined by the force applied and the geometry of the material.