Understanding Technical Drawing Concepts and Applications
1 – Difference Between Cuts and Sections in Technical Drawing: In the section, we illustrate the intersection between the plane surface drying and solid, while in the case of a cut, we depict the intersection and all that is behind the shear plane.
2 – Definition of Surface Slope: A developable ruled surface is a director cone of revolution. It is a type of surface with equal slope, assuming a curve in space, flat or warped. The points of this line are chosen as vertices of cones that remain homothetic and that will be moving cones maintaining their axes parallel, sliding their vertices on the curve.
3 – Definition of a Homology Limit Line: This is the locus of points on the plane that has its counterpart in the infinite. The distance from the vertex must be equal to the distance from the other axis.
4 – The Concept of Total Curvature and Mean Curvature of a Curve Element AC: The total curvature of an AC arc length s is defined as the angle of contingency (Y) formed by its extreme tangents. The mean curvature is given by the expression: c = (Y) / s, Cb = lim (Y) / s, C = 1 / R.
5 – Definition of Representational Systems: A systematic approach to elevate the elements forming any body in space, allowing the plane to resolve any problems that may arise regarding the solid. Three characteristics: 1) resource-based projects, 2) reversibility, 3) unambiguous. Dihedral projection uses cylindrical-orthogonal on two planes perpendicular to each other, namely the horizontal plane and vertical plane projection. The intersection of both planes is called the land line, using a flat auxiliary projection perpendicular to the other two planes, flat in profile. Dimensional drawings can work on a single project. Cylindrical orthogonal on a horizontal plane serves as a comparison. About the project, each point is placed with a figure that indicates the distance from the reference plane (level), which can be positive or negative. Axonometric projection is based on projecting orthogonally the cylindrical object in Cartesian axes and is called the picture plane or drawing plane. It manages four projections: direct and corresponding to each point p on the plans of the trihedral. Conical projection uses two processes central to the picture plane. The first concerns the geometry of the figure to represent. The second is given by the projection of the solid angle of a plane perpendicular to the picture plane, called the geometrical plane.
6 – What is a Homology? It is the relation of points that hold two characteristics: 1) all homologous points pass through the same vertex (O), and 2) all pairs of homologous points double points intersect in a line called the “axis.” Elements of a fundamental homology include: Vertex, straight axle limit. Fundamental properties and buildings. Homology in the flat: A homology is defined if three elements of it are known. When these three elements are central, and the first straight axis limit, it is the canonical definition of homology.
7 – Definition and Properties of a Homothetic Transformation: The particular case of the homology in the planes p1 and p2 are parallel, and the perspective center is a point itself. There is no limit or straight shaft. Any pair of homologous lines of f1 and f2 are contained parallelly, and figures are similar.
8 – Drying: The line joining two points of a curve that are not infinitely close. Tangent: The limit of two points drying when they are infinitely close, blending into one point called the point of contact. Normal: A perpendicular line to the tangent to a curve at the contact point.
9 – General Homology: The vertex O is a certain point in space, while the planes p1 and p2 intersect in a line. Affinity: The perspective center is located at infinity, and planes p1 and p2 are drying. There is no limit, but there are axis lines. Homothety: The planes p1 and p2 are parallel, and the perspective center is a point itself. There is no limit or straight shaft. Translation: The center of the homology is an improper point, and the planes p1 and p2 are parallel. There is no limit or straight shaft. The figures are identical.
10 – Functional Cota: When it is essential for the function of the part or hole. Non-functional Cota: It is not necessary for the hollow piece to fulfill its mission; it only provides an indication.
11 – Chilling: Known as the result of turning a plane around a straight intersection with the other two planes until they overlap, called the axis of rotation or hinge to this line.
12 – Intersection of Three Planes in Space Proves a Point: The relative position is one in which the planes intersect each other according to two parallel lines, and these three intersect at infinity in an improper point.
13 – Conceptual Error by Method of Slopes of the Profiles: If the flat slope obtained by the method of the profiles is trying to draw the horizontal plane, one might see that if sufficiently prolonged, these are not parallel. It follows that the obtained slope surfaces are not flat but warped surfaces of indeterminate law, and that the method of profiles is an approximate method that does not satisfy the geometrical laws derived from talus slope earth permanence. The method of profiles is accurate when the road has zero slope. The error will be nullified by decreasing the distance between the profiles.
14 – Why Are Radius Curves Used in Variable Road Layout in Plan? They are called “transition curves” and are variable radius curves that facilitate the gradual transition from a straight line to a circular curve or between two different radius circular curves. The mission of transition curves is to avoid the sudden appearance of centrifugal force produced by passing from a straight alignment to a curve. This is all the more necessary the greater the speed and the smaller the radius. Between the straight section and the circular curve is sandwiched a transition curve of length Lc, such that the increased centrifugal force per unit time does not exceed an acceptable value. The variation of cross slope does not exceed 4%.