How can we learn mechanics well

Engineering mechanics is an important technical basic course for mechanical posts, and many engineering practices are inseparable from engineering mechanics, which is closely related to other post courses and practice courses. Therefore, engineering mechanics is an indispensable and important course to master professional knowledge and skills. However, due to the poor foundation of technical school students, it is difficult to learn. Let me talk about how technical school students learn engineering mechanics. 1. Pay attention to mastering axioms, theorems, laws and basic concepts. There are many axioms, theorems and basic concepts in engineering mechanics, such as: the two-force balance axiom, the parallelogram axiom of force, the action and reaction axiom, the intersection theorem of three-force balance, the resultant torque theorem, Hooke's law, the concept of force, the concept of constraint and the concept of torque. We must memorize them, and at the same time, we must know their connotations and concepts. 2. Pay attention to integrating theory with practice. Engineering mechanics is the crystallization of human understanding and transforming nature. The basic laws of mechanics are summarized by people through long-term production practice and a large number of scientific experiments, through synthesis, analysis and induction. The need of production promotes the development of mechanics, and at the same time, mechanical theory in turn promotes the continuous development of production. Therefore, when studying engineering mechanics, we must pay attention to integrating theory with practice, observe carefully in life and production practice, be diligent in thinking, upgrade perceptual knowledge to rational knowledge, and apply theory to practice to test. For example, when we use a wrench to tighten nuts, we use a big wrench to save labor, and a small wrench is very laborious, which is easy to explain with the torque theory. Another example is steel bars with different diameters, both ends of which are stretched by external forces. When the force f increases to a certain value, it is known from experience that the fracture must occur in the section with smaller diameter, which verifies that the physical quantity to measure the strength of the component is stress. 3. Pay attention to the comparative study of many concepts, axioms and basic laws of engineering mechanics. We should pay attention to their relationship, compare their meanings and expressions, and find out their similarities and differences so as to truly understand and master them. Such as plane arbitrary force system, plane intersecting force system, plane parallel force system and collinear force system, their common point is that all forces are in the same plane, but the difference is that the direction of force and the action point of force are different; In the mechanics of materials, the similarity of four kinds of deformation is that the internal forces are all studied by section method, and the expressions of strength conditions are also very similar. The general formula σ = p/a ≤ [σ] can be used to represent σ = n/a ≤ [σ] in tension and compression, and τ = q/a ≤ [τ] and σ JY in shear and extrusion. The difference is that the deformation form is different; For example, the balance axiom of two forces and the axiom of action and reaction have in common that the two forces are equal in magnitude and opposite in direction, and act on the same straight line. The difference is that two forces act on the same object and two forces act on different objects. By comparison, we can understand and master concepts, laws and axioms in essence, improve cognitive ability, strengthen memory and improve comprehensive thinking ability. 4. Pay attention to mechanical models and assumptions. When solving engineering mechanics problems, the actual objects are often abstracted as mechanical models, or some assumptions are made about the objects, which greatly simplifies the problems and reflects the essence of objective things more accurately. We should pay attention to the mechanical model in our study. For example, the rigid body model in theoretical mechanics mainly changes the motion state when the object is stressed, and the deformation is very small; When calculating the internal force, the section method assumes that the internal force on the section is replaced by external force; Plane assumption for calculating stress, etc. 5. Pay attention to mechanical experiments. Many theories in engineering mechanics are based on experiments, such as the mechanical properties experiments of materials under tension and compression. When doing experiments, we should carefully observe and record the data, carefully study the experimental results, verify the correctness of mechanical theory with experiments, and enhance our confidence in learning engineering mechanics. 6. Pay attention to solving application problems. Solving application problems is a key point in engineering mechanics learning. The level of problem-solving ability is not only a measure of students' mastery of basic concepts and laws, but also a measure of students' comprehensive analysis ability and problem-solving ability. By solving problems, we will find many regular things. For example, the equilibrium equations of all plane force systems are the evolution of equations ∑Fix=0, ∑Fiy=0 and ∑Mo(Fo)=0. When we draw the stress diagram, it is not easy to draw less, more or wrong forces on the stress diagram as long as we strictly follow the following steps, that is, first determine the research object and draw the separation volume diagram, and then analyze the constraint type and the direction of constraint reaction of the research object. In a word, although engineering mechanics is a difficult course, I think we can learn it well as long as we have firm confidence and use scientific and effective learning methods.