the reaction force in structural mechanic
In structural mechanics, structural reaction could also be referred to as reaction force. In a broad sense, it was a reaction force in mechanics. In the aspect of building structure system, when external factors act on the structure, in order to achieve the force balance of the structural system, the force provided by the structural support is the structural reaction force. There were two types of reaction forces: one was the concentrated force, which was an external force that acted on the component and the surface area was much smaller than the size of the component; The second was the form of the bending moment (or couple). The bending moment was a type of internal force moment on the cross-section of the bearing component. In layman's terms, it was the moment required for bending. It stipulated that the lower part was pulled positively (the upper part was pressed), and the upper part was pulled negatively (the lower part was pressed). Its standard definition was the joint force couple moment of the distributed internal force system vertical to the cross-section. The calculation formula was M = 0·El/L (0 was the rotation angle, El was the rotation stiffness, and L was the effective calculation length of the bar). The reaction force could provide an equilibrium condition for structural calculation, which could be used to calculate the internal force of the structure and further analyze the structural distortion. In some structural analysis methods, the static indeterminate support form would be reduced by assuming a reaction force. This assumed reaction force was called static indeterminate residual force or redundant force. The reaction force was categorized into flexible body constraints, smooth contact surface constraints, movable hinged bearings, fixed hinged bearings, fixed end bearings, and so on. In addition, it was not enough to rely on the static equilibrium equation to solve the reaction force of the static indeterminate structure. It was necessary to supplement the equation with the distortion condition. The internal force and reaction force of the static indeterminate structure were related to the physical properties of the material and the geometric characteristics of the section (shape and size). Non-load factors (such as temperature and support movement) could also cause the internal force and reaction force of the static indeterminate structure. It was relatively easy to solve the reaction force of the support of a static structural beam. The reaction force of the support could be obtained by replacing one support with an external force and then calculating the total bending moment of all external forces on the other support. Read more exciting novels for free
What is the reaction force of the support in structural mechanics?
For the solution of the support reaction force of a static structural beam, the following methods can be used: Remove a support (such as support A) and replace it with an external force.(That is, the reaction force of the support, the line of action, and the canceled support member are overlapped, and the direction is generally upward). Then, all the external forces are applied to the other support to calculate the bending moment (note the positive and negative signs). Since the static beam will not rotate, the total bending moment of all external forces (including the reaction force of the support A) to the other support should be "0", so the reaction force of a support can be calculated (note the + sign indicates that the reaction force of the support is in the same direction as the assumed reaction force of the support, otherwise it is opposite). Similarly, the reaction force of the other support could be obtained. In addition, after finding the reaction force of a support, the reaction force of another support could also be found under the condition that all the support reaction forces were equal to all the external forces. For a simply supported beam, static equilibrium could also be used. In the vertical direction, there was always the equation of F = 0, and for the hinged point, there was the equation of M = 0. For the continuous beam, rigid frame and other indeterminate structures, the force method or displacement method should be used to calculate the support reaction force. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is the formula for the reaction force of the support in structural mechanics?
For a simply supported beam, the static equilibrium could be used to calculate the support reaction force, that is, in the vertical direction, there is always an equation of F = 0, and for the hinged point, there is a equation of M = 0. For the continuous beam, rigid frame and other static indeterminate structures, it should be calculated by force method or displacement method. The calculated vertical force is the reaction force of the support. The specific calculation of the reaction force of each support is the calculated vertical force of the support divided by the number of supports. In addition, the formula for calculating the reaction force of the support was also: Ri + Ri = P (where P was the external force, Ri and Ri were the reaction force of the support). For the frame structure, if the external force of the structure is balanced, then the equation of x=0 is xA=0; the equation of y=0 is Ya+Yb=4P (where 4P is the sum of external force, Ya and Yb are the reaction force of the support). By using the load and shape symmetries, Ya=Yb= 2P. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The difference and relation between reaction force and moment in structural mechanics
In structural mechanics, the reaction force and the moment were both different and related. ** 1. The difference ** 1. ** In terms of definition ** - Reaction force: In a broad sense, it was the reaction force in mechanics. In a building structure system, when external factors acted on the structure, in order to achieve the force balance of the structural system, the force provided by the structural support. There were roughly two types of it, one was the form of concentrated force (if the external force acting on the component was far smaller than the size of the component), and the other was the form of bending moment (or couple). - Moment: A measure of the effect of force on the rotation of a rigid body. When a force F is applied on a plane, take any point O in the same plane (the point O is called the moment center). The vertical distance h from the point O to the line of action of the force is called the arm of force. The moment of the force to the point is an algebra. Its absolute value is equal to the product of the force and the arm of force. When the force makes the object rotate counterclockwise around the moment center, it is positive. Otherwise, it is negative. 2. ** Physics ** - The reaction force was mainly from the perspective of structural balance. It was the force generated by the structure in order to resist external loads. It reflected the interaction between the structure and the support, and was the key factor to maintain the overall balance of the structure. - Moment was more about the effect of force on the rotation of an object. Its size depended on the size of the force and the length of the arm of force. It was related to whether the object rotated around a certain point and the trend of rotation. 3. ** Calculation and representation ** - The calculation of the reaction force needed to be based on the force analysis of the structure, using the static equilibrium equation (such as Fiend Fx = 0, Fiend Fy = 0, Fiend M = 0) to solve. The result was the magnitude and direction of the force, and the unit was N (Newton) or Thousand-Newton (Thousand-Newton). - The calculation of the moment was the product of the force and the arm of force (M = F×h). It was an algebra, and the unit was N·m (Newton·m) or GN·m (KiloNewton·m). ** 2. Contact ** 1. In terms of structural calculations, - The reaction force and the moment were related in the structural calculation process. For example, when calculating the internal force of a structure, the reaction force was an important known condition or solution target, and the calculation of the moment was often related to the reaction force. When calculating the bending moment (a type of moment) of a beam, the reaction force at both ends of the beam needed to be considered. The static equilibrium equation was used to determine the bending moment distribution at different positions on the beam. 2. In terms of structural balance - The overall balance of the structure required both the balance of force (the counterforce played an important role) and the balance of moment. For a structure in a state of equilibrium, while the forces were balanced, the reaction force was involved, and the moment was balanced. None of the three could be missing. The existence of the counterforce could provide a balancing moment to ensure that the structure would not rotate or move when subjected to various loads. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is the principle of calculating the bearing reaction force in structural mechanics?
The principle of calculating the reaction force of the support in structural mechanics is based on the principle of force equilibrium. First of all, he had to determine the force on the object, including gravity, external force, etc. He could use the free-body diagram to represent the force point and direction. Then, the force balance of the object was calculated along the horizontal and vertical directions. For the balance of force in the horizontal direction, the reaction force in the horizontal direction is usually zero or equal to the external force in the horizontal direction; for the balance of force in the vertical direction, the reaction force in the vertical direction is usually equal to the gravity of the object or equal to the external force in the vertical direction. The calculation formula of the bearing reaction mainly included the equilibrium equation and the moment equation. The equilibrium equation states that when an object is in a state of static equilibrium, the resulting force and moment of all forces acting on the object are zero. In the calculation of the reaction force of the support, the equilibrium equation of the object was usually divided into two equations in the horizontal direction (where the sum of all the forces acting on the object in the horizontal direction was zero) and the vertical direction (where the sum of the forces in each direction was set to zero and the equation system was solved, the magnitude of the reaction force of the support could be solved. In addition, according to the type of support (such as fixed support, hinged support, etc.), the shape of the object, the way the force is applied, and other factors, the specific calculation method will be different. Complex force situations may require more complicated mechanical methods to calculate. For some special beam structures, there were some simple calculation methods. For example, for a simply supported beam under symmetrical load, the support reaction force could be divided into half by the symmetrical load, that is, the two supports each bear half of the load. For a simply supported beam under a biased load, the support reaction force could be calculated by the inverse ratio of the biased load. The support reaction force at one end of the beam was equal to the ratio of the distance from the point of action of the load to the other support and the length of the beam span multiplied by the size of the load. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The structural requirements for the elimination reaction of substituted aromatic compounds
The following structural requirements must be met for the elimination reaction of the halalocarbon: 1. The number of carbon atoms in the molecules is greater than or equal to 2. 2. The existence of beta-H meant that there must be a hydrogen atom on the carbon atom adjacent to the carbon atom attached to- X. 3. The halo atoms on the ring cannot be eliminated. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The relationship between binding force and binding reaction force is
Binding force and binding force were a pair of balanced forces. The strength of the binding force increased with the increase of the binding force and decreased with the decrease of the binding force. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Reaxff reaction force field principle
ReaxFF was a molecular force field based on bond level. It is commonly used in molecular dynamics simulations. Goddard and his collaborators at the California Institute of Technology suggested. In its simplest form, as a bridge between chemical quantum and the experiential force field, it used a set of relatively simple functions to describe the relationship between energy and geometry. For example, it used the EFF method to deal with the simple harmonic-wave equation of the condensed matter system. These equations were used to describe the stretching, compression, and bending of bond angles. However, the current reference materials did not have more in-depth information about its principle, so it was impossible to answer further. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to Find the Formula of the Reaction Force of the Support
The calculation formula of the bearing reaction mainly included the equilibrium equation and the moment equation. When calculating the reaction force of the support, the equilibrium equation of the object was usually divided into two equations: the horizontal direction and the vertical direction. For the balance equation in the horizontal direction, the formula, F x = 0, can be used. This formula means that the total force of all forces acting on the object in the horizontal direction is zero. When calculating, all the horizontal forces on the object (including external forces and support reactions) need to be added. At the same time, when using the moment equation, the couple relationship between the support reaction force and other forces should be considered. According to the specific force situation of the structure, the relevant equations should be listed, and then the support reaction force should be obtained by solving the equation. For example, in some structures, if the support reaction forces FA and FO form a couple in opposite directions, it is necessary to list the equation and solve it according to the overall force balance. For the case of structural external force balance, such as the conditions of x=0, y=0, etc., can also be used to solve the support reaction force. For example, in the framework structure, the support reaction force can be obtained by the method of x=0 to get XA=0, y=0 to get Ya+Yb=4P, and then the load and shape are symmetrical to know Ya=Yb= 2P. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Bearing reaction force of super static structure
The reaction force of the support of a hyperstatic structure is related to the physical properties of the material and the geometric characteristics of the cross-section (shape and size). Non-load factors (temperature, support movement) will also cause the internal force and reaction force of the hyperstatic structure. For the calculation of the reaction force of the support of the indeterminate structure, such as the continuous beam, rigid frame and other indeterminate structures, the force method or the displacement method should be used. When the simple-supported-to-continuous bridge structure is pre-fabricated into a simple-supported structure, it is a static system without bearing reaction force. After the post-tension tendons are stretched, the tension will affect the internal force and cross-section stress of the structure. After the structure forms a continuous system, the analysis of contraction, creep and uneven settlement of the bearing should be calculated according to the continuous beam system. At this time, the secondary internal force and internal force re-distribution should also be considered. For the calculation of the support reaction force of the continuous beam in the hyperstatic structure, if it was a hyperstatic structure, the vertical support reaction force could be selected as the surplus force, and the force method equation could be established to obtain one support reaction force, and the other two could be solved according to the hyperstatic structure. The load distribution corresponding to the maximum reaction force of the support is that the two adjacent spans on the left and right of the support are filled with live load, and then the other spans are filled with live load; or the two adjacent spans on the left and right of the support are not filled with live load, and then the other spans are filled with live load. When calculating the reaction force of the support of a hyperstatic structure, different structural forms (such as the difference in the calculation results of a wide bridge using a grillage model or a single beam model) and different load combinations (such as temperature grads and uneven settlements) will affect the results. The internal force and support reaction force calculated by the single beam model of the wide bridge deviated greatly from the actual situation. The influence of temperature grads and uneven settlement on the reaction force of the small-span wide continuous beam bridge was very large. Under the combined effect, the negative reaction force of the supports at the pier and the abutments might appear. When there were more than two horizontal supports, the reaction force of the adjacent supports was quite different. The possibility of negative reaction force appearing on the outer support at the abutments and the inner support on the abutments was relatively large. In structural design, increasing the length of the pile to reduce the uneven settlement of the foundation, reducing the thickness of the slab, and reducing the stiffness of the main beam can obviously reduce the probability of the negative reaction force of the support, while adjusting the side-to-mid-span ratio has relatively little effect. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What are the sequence, structural relationship and structural features of the article?
The relationship between sequence and structure refers to the relationship between the sequence and structure of the plot development in the novel. The structural features refer to the characteristics of the entire structure of the novel, such as: - The plot is formed by a series of events that unfold in a certain order. - Non-linear structure: The plots do not unfold in a linear order, but there are complex turns and progression relationships. - Thematic layered structure: The plot and character activities are interconnected on multiple levels, and the theme is gradually deepened. - Time travel structure: The plot spans multiple time and space dimensions and the characters experience different historical backgrounds. - Multiple narrative structure: Through multiple perspectives and conversations between multiple characters, different plots and story lines are presented. The plot, character relationships, theme, and meaning in the novel often presented complex structural characteristics that required the reader to think deeply and explore.