1. At the same time, using the force diagram of curves intuitive to judge design calculation results'rationality visually omits the trouble in the manual verification.

2. In mechanical project calculation , Drawing internal force diagram is very important. With respect to complex internal force diagram, this paper presents some simplification methods of drawing.

3. To learn engineering mechanics and do engineering computation, we must master the drawing methods of internal force diagram.

4. To analyze the nonskid condition of the longitudinal knife of the splitting machine based on its force diagram, which provides theoretical basis for designing longitudinal knife.

5. Especially it is easy to make errors in drawing internal force diagram of a beam because the rules are too more to memory.

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6. By theoretical analysis, the considerations were put forward about the check with symmetry solving hyperstatic structure, avoiding internal force diagram check errors caused by inertial thinking.

7. Two factors can lead to pitch instability: no or too small horizontal stabilizers (h - stabs) on too short a tail and high thrust line propeller placement which destabilises the force diagram.

8. In this paper, a new hardware circuit of real time measuring for mine hoist force diagram based on alternating current sampling is proposed. The software algorithm is also given in the paper.

9. This method can not only be used to draw shear force diagram quickly, but also to determine the shear sign automatically, and to verify the reaction force of multi-span beam.

10. The particle route method is produced for the shear force diagram drawing of multi-span beam based on the geometric principle of the force addition.