What are the dynamic characteristics of a structure? What factors are involved

Structural dynamic properties are properties inherent to the structure, including natural frequencies.

Damping, mode shapes.

They are only related to the mass, stiffness, and material of the structure.

A modern method of dynamic properties of structures, modal analysis.

Based on the vibration theory, the modal parameters are taken as the objective function, and the modal parameters of the system are identified as the ultimate goal, which provides theoretical support for the vibration analysis of the structure, the fault diagnosis of the equipment and the optimization of the dynamic characteristics of the structure.

The dynamic characteristics of the structure refer to the three main aspects of the natural vibration period, mode shape and damping ratio of the structure. The so-called mode shape refers to the basic form of structural vibration, and generally the structure has several layers and several mode shapes, which correspond to several periods. Usually the first mode shape is dominant, and several other high mode shapes decay quickly.

The commonly used basal shear method is calculated from the first mode shape. The damping ratio refers to the ratio of the vibration damping coefficient of the structure to the critical damping coefficient, which is also inherent in the structure itself.

Structural dynamic analysis mainly includes three parts: eigenvalue analysis, response spectrum analysis, and time history analysis.

Eigenvalue analysis, also known as structural natural vibration characteristic analysis, mainly requires the interpretation of the natural vibration period and mode shape vector of the good and bad structure.

Response spectrum analysis is based on the theory of mode decomposition response spectrum, which is the most commonly used method in engineering to calculate the dynamic response of structures under the action of **, but this method is limited to linear elastic structures, and the mode shape decomposition method in the elastoplastic stage is no longer applicable.

The main difference between the time history analysis and the mode decomposition method is that the response of the structure is calculated by using the measured ** wave tremor input structure, and the elastoplastic time history analysis can also be divided into two categories: static elastoplastic time history analysis (also known as pushover analysis) and dynamic elastoplastic time history analysis.

Among the above-mentioned structural dynamic analysis, eigenvalue analysis and response spectrum analysis are commonly used. Time-history analysis is generally only for important buildings and buildings of very complex size. The time history analysis of structural line elasticity can be carried out under the small earthquake level, and the structural elastoplastic time history analysis method is required under the large earthquake level.

At this stage, elastoplastic time history analysis is still a relatively cutting-edge analysis content in engineering, and it also belongs to the "patent business" of some strong design institutes and scientific research institutions. Of course, with the continuous improvement of the level of structural technicians and the development of software technology, structural elastoplastic time history analysis will become more and more popular in the future, and even become a "commonplace" for structural designers.

Answer]: a, b, c

The chiropractic test is an important part of the dynamic test, and it mainly includes basic parameters such as natural frequency, damping coefficient and mode shape.

Factors that do not affect the dynamic characteristics of the structure include:

Mass distribution: When the mass distribution of an object is uniform, it does not affect its structural dynamic properties.

2.Temperature: Within a reasonable temperature range, temperature changes will not have a significant effect on the dynamic characteristics of the structure.

3.Acceleration: When the acceleration of an object does not exceed the limits of what its structure can withstand, it does not have a noticeable effect on the dynamic characteristics of the structure.

4.Neutral axis position: When an object's neutral axis position is the same as the position in the previous design, there is no effect on its structural dynamics.

5.Inertial force: Within a reasonable range of inertial forces, inertial forces do not have a significant impact on the dynamic characteristics of the structure.

It is important to note that the above factors may be affected by other factors, especially in high-speed movements or complex environments. Therefore, a comprehensive analysis and evaluation of the dynamic characteristics of the structure is essential to ensure health and safety.

Answer] The dynamic characteristics of the :d structure include the natural frequency of the closed wax structure, the car slip, the mode shape and the damping coefficient. The amplitude is the dynamic parameter of the structure under dynamic load, and does not belong to the dynamic characteristics of the structure.

An important physical parameter reflecting the dynamic characteristics of a structure is the natural frequency of the vibrating particles

Summary. Kiss <>

Hello, I will come to the application of the dynamic characteristics of the structure in life is that the dynamic characteristics of the structure have a wide range of applications in life, mainly reflected in the fields of architecture, transportation, aviation, electronics, machinery and other fields. In the field of architecture, the dynamic properties of a structure are one of the most important factors in the design of buildings. The structure of the building should have sufficient strength and rigidity to withstand natural loads such as wind, snow, **, etc., and be able to maintain its form stably.

At the same time, the dynamic characteristics of the structure will also affect the vibration characteristics of the building, so attention should be paid to controlling the vibration when designing, so as not to affect people's use and comfort.

The application of the dynamics of the structure to life.

Kiss <>

Hello, I will come to the application of the dynamic characteristics of the structure in life is that the dynamic macrological properties of the structure have a wide range of applications in life, mainly reflected in the fields of architecture, transportation, aviation, aviation, aviation, electronics, machinery and other fields. In the field of architecture, the dynamic properties of a structure are one of the most important factors in the design of buildings. The structure of the building should have sufficient strength and rigidity to withstand natural loads such as wind, snow, **, etc., and be able to maintain its form stably.

At the same time, the dynamic characteristics of the structure will also affect the vibration characteristics of the building, so attention should be paid to controlling the vibration when designing, so as not to affect people's use and comfort.

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Dynamics of structuresIn the field of transportation, the dynamics of structures also play an important role. For example, the body of the car should have sufficient rigidity to withstand the acceleration, turning, braking and other forces during driving, and at the same time, the vibration of the car in the process of road driving should also be considered, so as to ensure the comfort and safety of passengers. In the field of aviation, the dynamics of the structure are also one of the key factors in the design of aircraft.

The fuselage manual structure of the aircraft should have sufficient strength and rigidity to withstand the aerodynamic, gravitational force, centrifugal force and other loads during the flight, while also considering the aircraft.

When calculating the dynamic characteristics of a structure, the principle of intrinsic properties of the structure should be followed.

They are only related to the mass, stiffness, and material of the structure. Modal analysis is based on vibration theory, with modal parameters as the objective function, and the ultimate purpose of identifying the modal parameters of the system, which provides theoretical support for the vibration analysis, equipment fault diagnosis and optimization of structural dynamic characteristics.