The first strength theory is applicable to brittle materials; then, is it reasonable to use the first strength theory for plastic materials as specified in GB150 as well?
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The first strength theory is applicable to brittle materials; then, is it reasonable to use the first strength theory for plastic materials as specified in GB150 as well?
The last edit to this post was made by Take a look_knkRj on 2025-4-11 at 10:27. 1. Apart from mathematics, the conclusions in all other subjects are derived by summarizing engineering/experimental patterns; if all or most of the cases are correct, using the first theory does not pose any problem. It’s not necessary to strictly follow the book. 2. (From the training course for pressure vessel design engineers) It was developed early, ample experience has been accumulated, the calculations are simple, and the requirements regarding materials, manufacturing, and inspection are less stringent than those in analytical design. So it is widely used.
Also, in the case of triaxial tension, if the values are extremely high, according to the third and fourth strength theories, failure should not occur; yet this clearly does not match reality or experimental results. This also shows that it’s not necessary to follow the books strictly
It’s unreasonable. The first strength theory is mainly applicable to brittle materials. For plastic materials, the second strength theory or other more suitable strength theories are generally used for strength verification. The strength theory suitable for plastic materials should be used for the forming materials in GB150. .