What are the differences between axial, bending, and shear loads?

Axial loads are forces that act along the longitudinal axis of a structural element, either in tension or compression (pushing together). The magnitude of stress at any point along the cross-section is the same, and the load is distributed over the entire cross-section Bending loads are forces that cause a structural element to bend. The magnitude of the shear stress becomes important when designing beams in bending that are thick or short. Shear loads on the other hand are forces that act parallel to the cross-section of a structural element.

Axial, bending, and shear loads exert unique forces on structural elements like beams or columns: Axial Load: Operates along the structural axis, causing compression or extension. Example: A column supporting a vertical load. Bending Load (Moment): Induces bending or flexing, creating compression and tension. Example: A beam supporting a distributed load. Shear Load: Acts parallel to a material's surface, causing sliding and deformation. Example: Cutting paper with scissors. This breakdown unveils the dynamic forces shaping structural integrity, providing a clear understanding of how elements respond to compression, bending, and shearing forces.

Axial load is defined as an external force acting along the axis (length) of an object; it is also known as tension or compression depending on whether it increases or decreases length respectively within an object’s material properties limits . Axial loading occurs when two opposite forces push against each other along one direction which causes stress in that particular direction only while leaving no room for movement sideways from either side due to being equally balanced out by both sides pushing against one another with equal intensity . This type of loading typically results in linear deformation meaning any changes made to shape will be uniform throughout all directions affected by axial load like stretching/shrinking etcetera .

After rolling the a steel section the net axial load on the section are zero. The internal stresses from the rolling are NOT uniform across the section. So if ad pure axial tension of compression you still end up with non uniform stresses. So apply a huge amount of strain gauges to a steel beam and cut close to the train gauges why do you get readings. No Load just internal stress relieve. Poisson's ratio will mess with your stresses depending of the end restraints your section has! Unless you concrete structure is under water it will shrink form the outside of the section toward the inside. This sets up axial stresses in a unloaded section which then get partial ameliorated by creep! Stress is NEVER the same across any section!!!

D'après ma simple expérience. - Charges axiales : Dans un repère tri-dimensionnel XYZ, les charges axiales sont des efforts appliqués dans la direction du repère local de section. Ainsi on aura 2 directions d'efforts tranchant Ty,Tz et une direction d'effort sur l'axe neutre N - la charge de flexion : celle-ci est une contrainte pouvant générer un moment de flexion, indépendant de l'effort tranchant elle est souvent assimilé à un couple de forces équivalentes dans la zone de concentration des contraintes - le cisaillement est dans la plupart des cas généré par un effort tranchant Ty ou Tz A la différence de l'action des moments, la réaction d'un élément face à la sollicitation d'un effort est assimilée à une surface/section résistante.

Bending Load refers to a lateral force applied perpendicular across some part's cross sectional area resulting into curvature formation instead ,Bending moments occur when two opposing forces apply pressure at different angles causing them not just stretch but bend materials away from their original form which means they require much higher tensile strength than those subjected under pure axially loaded conditions alone - thus making them ideal candidates for use cases where flexibility needs must remain intact despite considerable amount weight bearing down upon them over time without breaking apart easily during regular usage scenarios like chairs/tables etcetera.

La localización de un momento positivo o negativo en un elemento sometido a flexión, se evidencia en aquellas zonas donde el miembro estructural experimenta tracción, lo que implica que en estas zona debe proporcionarse acero refuerzo para el caso de concreto reforzado o una sección suficiente para matiales como acero o madera para que de esta forma pueda atender las solicitaciones a tracción.

Axial loads act along the length of a structure, like the weight of a stack of books. Bending loads cause a structure to bend or flex, as seen in a diving board. Shear loads apply parallel forces in opposite directions, like scissors cutting paper. Each type of load has distinct effects on structural elements.

Bending loads correspond to forces that produce flexure on an element. In this case, the flexure could be produced by the eccentricity of an axial load or a load applied perpendicularly on the axis of an element producing flexure. Bending loads will incur in both tension and compression fibers in the cross-section of the element.

Bending forces are applied in many everyday situations. The bending force from leaning back in a chair applies a bending stress to the portion of the chair where the backrest is fixed to the seat. Someone who is climbing a ladder leaning up against a fixed object is applying a bending force not only to the fixed ends of the ladder, but also to the individual fixed ends of each rung of the ladder.

There are many ways to think about shear: Shear force is the way that an applied force on a beam transfers to the reactions. While it can be helpful to think of a shear force acting in a particular direction, such as perpendicularly across a beam section, this is just a useful fiction. Imagine the beam as line of books: shear is the force overcoming the friction between the books. It is the rate of change (differential) of a bending moment. When considering stresses, shear is when you have tension and compression at right angles to each other. At the fundamental level, strain, shear is a square of material lozenging. One diagonal becomes longer (tension) and the other shorter (compression).

Think of a scissors-papre relationship. When you cut paper with scissors, you're essentially applying a shear load to the paper. The scissors work by using shear force to slide one blade past the other, creating a cut. In structural engineering, shear load is a force that acts parallel to the surface, trying to slide one part of a structure past another.

In simple terms, shear load are not any different category of loads/forces but are the loads which produce shear/tangential stresses (acting along the face/surface perpendicular to longitudinal direction) in the member. Where normal stresses tend to change the dimension (volume) of member, shear stresses tends to change its shape. Torsional couple (torque) induced by two equal and opposite axial loads about longitudinal axis of a circular bar is perfect example of pure shear load as it induces pure shear in the member at any section.

Shear, like all forces and stresses, is a construct. It emerges as a way to allow the change of direction of forces in a continuous body.

Read about the Modified Compression Field Theory (MFCT) in the Publications of M. C. Collins at all and then you learn about principle stress directions and magically shear and bending no longer exist and every part of the concrete elements making up a structure experiences principal stresses along their changing principal axis. In 1990 when I presented my thesis which was only a 2D computerized version of the MFCT. A young professor was asking a review question: "So its just compression and tension in different direction and there is not shear?". Even so he came from a well known university, he demonstrated is limited knowledge of advance mechanics. I agree with Peter Debney, it is a useful fiction for designing simple members.

Load combinations are specified by building codes, standards, and engineering practices to ensure that structures are designed to withstand the most critical and realistic combinations of loads. These combinations are typically determined based on statistical analyses and historical data to represent the most severe conditions that a structure may experience. By considering various load combinations, structural engineers can ensure that structures are designed to be safe and reliable under a wide range of scenarios, thereby minimising the risk of failure and ensuring the well-being of occupants and the public.

Whoever came up with the 750 character limit for all these topics should be taken behind a barn so it can be explained why not all topics can be reduced to just a few words of only 750 characters!

Ma conclusion comparative, les charges axiales agissent le long de l'axe de l'élément, les charges de flexion provoquent une déformation de courbure et les charges de cisaillement agissent de manière parallèle et opposée à une section ou une surface.

Steps for load analysis: Identify and quantify the different types of loads that a structure is expected to experience during its service life by considering both dead loads and live loads, as well as wind, snow, and seismic forces. Determine the appropriate combinations of loads to be considered during the design process. Create a mathematical model of the structure to simulate the behavior of the structure under the applied loads. Apply engineering principles and analytical methods to calculate the internal forces, stresses, and deformations within the structure under the specified load combinations. Assess the results of the load analysis to ensure that the structure meets safety, performance, and serviceability requirements.

An example of the importance of load analysis is how it inform structural design of structures, also it determines if section of a building are adequate to satisfy both ultimate and serviceability limit state

Load analysis without considering the construction sequence leads to fictional answers when dealing with modern cable-stayed bridges that have concrete towers that composite decks. As we build the tower it starts to shrink when we take the form work away and jack it up. The tower section experiences more axial load in various increments, which cause different amounts of creep on each tower element as construction proceeds. Part of this is compensated when the forms are set to elevation for the next pour. But at the end of construction the tower will continue to shrink and creep for the decades to come. So we have to account for this considering all time/load steps and build the towers taller. Decks just don't fit in a 750 character limit!

As a structural engineer, it is important to recognize that the text you provided does not mention the concept of torsional forces, which is a significant aspect in structural engineering. Torsional forces refer to the twisting or rotational forces that act on a structure, often caused by applied moments or uneven loading. These forces can have a substantial impact on the behavior and design of structures, particularly those with elongated or asymmetrical shapes. Understanding torsional forces is crucial for assessing the structural integrity of various elements, such as beams, columns, and shafts. Neglecting to consider torsional forces can lead to inaccurate analyses and potentially compromised structural stability.

First and second order analysis: First order analysis (linear) assumes that the structure behaves in a linear manner under loading. It is typically used for simpler, more straightforward structural problems where the load is relatively small and the deformation of the structure is expected to remain within the linear range. Second order analysis (nonlinear) takes into account the effects of geometric and material nonlinearities on the structure's behavior. This method is used when the load on the structure is large enough that it causes significant deformation. It is more complex than first order analysis and requires more advanced computational methods. It provides a more accurate representation of the structure's behavior under load.

The loads that act along the longitudinal axis of members e.g. earth pressure from the retaining side and the earthquake forces. Bending forces are due to the loads acting at a distance along perpendicular axis of members whereas shear force is sliding force of a member.

In simple words: 1. Axial loads : stretching or squashing force. 2. Bending loads : pushing force 3. Shear loads : cutting force