一様曲げ変形（モーメント軸が流れ方向）を受ける段ボールの応力解析 第４報 厚さ方向に非対称な強度をもつ両面段ボールの場合

Abstract

Analysis of the bending stress in single wall corrugated fiberboard (SWCF) with asymmetrical strength distribution for the thickness direction (normal to the kraft-liner (KL)) is performed, and relations between maximum of absolute stress σ smax, σk1max and σk2max and shape for upper KL (KL1), lower KL (KL2) and SMP medium (CM, (thickness Ts : wavelength L : wave height h)) are discussed. Then relations between strength Efs, Efk1 and Efk2 per mass and shape factor are obtained.(1) Distance h0 between neutral surface and thickness for SWCF moves to KL1 side with the increase of Young's modulus Ek1 and thickness Tk1 of KL1. h0 decreases obviously with the increase of Ts and increases with the increase of h. And h0 increases gradually with the increase of L.(2) Positions of maximum stress for CM and KL move to KL2 side with increase of Young's modulus Ek1 and thickness Tk1 of KL1. Their maximum stresses for CM and KL are on the other outer surfaces.(3) σ smax, σk1max and σk2max decrease with the increase of the thickness Ts and wave height h for CM. σsmax, σk1max and σk2max increase initially and then decrease with the increase of the wavelength L for CM. Then the maximum values appear with the increase of L.(4) Efs decreases with the increase of Ts, and increase with the increase of L and h. Efk1 and Efk2 increase with increase of Ts and h, and decrease with the increase of L.