Answer
Matsakaicin damuwa yayin shigarwa yana faruwa lokacin da aka faɗaɗa zobe a kan wani shinge ko kwangila a cikin gidaje. An ƙididdige damuwa na shigarwa $ S_i $ a matsayin $ S_i = \ frac {E \ cdot t \ cdot (D_g - D_f)}{D_f \ cdot D_g}$, inda $ E $ shine modulus, $ t $ shine kauri na kayan, $ D_g $ shine diamita shigarwa (shaft ko gidaje), kuma $ D_f $ shine diamita na kyauta. Don hana saiti na dindindin (nakasar filastik), $S_i$ dole ne ya wuce ƙarfin yawan amfanin ƙasa $\sigma_y$ na kayan. Idan $S_i> \sigma_y$, zoben ba zai dawo zuwa ainihin diamita na kyauta ba, wanda zai haifar da sako-sako a cikin tsagi. Don kayan kamar SAE 1070, iyaka shine yawanci $ 200,000 $ psi. Idan aikace-aikacen yana buƙatar faɗaɗa wuce gona da iri, dole ne a ƙera zoben tare da juyi da yawa ko ɓangaren giciye don rarraba nau'in lanƙwasawa.
