Strength prediction of braided composite plates with a center hole

Abstract

In this study, the notched strengths of three kinds of braided composite plates with a center hole were investigated. Both point stress criterion (PSC) and average stress criterion (ASC) were first applied to find the characteristic length of each braided composite plate with different sizes of the hole. It was found that the characteristic lengths predicted by both criteria are not constants. Based on the concept of three-parameter criterion, the characteristic lengths obtained by both criteria were then proposed to be expressed as functions of hole size as well as width of the plate. The notched strength of braided composite plates was then predicted. Finally, it was shown that both modified PSC and modified ASC gave better predictions of the notched strength than traditional PSC and ASC for all the kinds of braided composite plates.

Finite Element Based Point Stress Criterion for Predicting the Notched Strengths of Composite Plates

“…Based on the predicted characteristic lengths, the finite element analysis results and the principle of superposition in elasticity, the notched strengths of composite plates are acquired and listed in Table 3. From Table 3, it is evident that the computational results by FEBPSC agree well with the experimental results [25]. Moreover, the predicted notched strengths both from FEBPSC and ASBPSC [25] are very close.…”

“…From Table 3, it is evident that the computational results by FEBPSC agree well with the experimental results [25]. Moreover, the predicted notched strengths both from FEBPSC and ASBPSC [25] are very close. Table 1 The mechanical properties of 3K-144 braided carbon/epoxy composite [25] Composite Identification …”

“…Moreover, the predicted notched strengths both from FEBPSC and ASBPSC [25] are very close. Table 1 The mechanical properties of 3K-144 braided carbon/epoxy composite [25] Composite Identification …”

“…To verify the capability of FEBPSC, the results from experiments and analytical approach in our previous work [25] are first employed for comparison. The material properties of specimens of 3K-144 braided composite plates are listed in Table 1.…”

“…They were then modified into three parameter models based on experimental evidence [5,6]. These criteria can be extended to include any laminate of symmetric construction by using the anisotropic plate solution discussed by Lekhnitskii [4] Traditionally, analytical solutions [15][16][17] were required in predicting the notched strengths of composite plates, as a result both PSC and ASC were only applied for predicting the notched strengths of composite plates each with a center hole [18][19][20][21][22][23][24][25], which may be either circular or elliptic. Therefore, to predict the notched strengths of composite plates each with arbitrary shape of notch located either at the edge or in the center of the plate by both PSC and ASC is still out of reach up to now.…”