In addition to the ballistic test, where force was applied vertically to the fabrics, the intra-ply stretchability was explored using first-principles calculations (Supplementary Information, Figure ). The presence of the highest entanglement density in the plain weave has the lowest energy among the three optimized weaves without stretching. Before the strain ratio is up to 3%, the total energies of these woven patterns exhibit subtle change. When forces are further applied in both weft and warp directions, stretched strands prompt a significant rise in total energy (Box 1d). Certainly, the energy of the plain weave increases more rapidly than the other two weaves at the same strain ratio, indicating that the plain weave possesses the lowest flexibility due to its highest entanglement density. At a strain ratio of 9%, the total energy increase across the three weaves follows this ranking: plain weave (22.5 eV) > mix weave (22.1 eV) > basket weave (16.8 eV), correlating positively with the number and density of entanglements and interstrand interactions (Fig. ). The differential charge density (DCD) provides additional confirmation that the stretching-induced breakage of hydrogen bonds (C-H‧‧‧N) and the weakening of aromatic p-p stacking collectively contribute to the stretchability of weave, evidenced by the shift of electron migration area from the interlacing field to the contact field (Fig. ). In contrast to the significant energy increase observed in the entire weaving structure (around 20 eV), the energy changes induced by stretching in free individual strands are 20-30 times lower (around 0.9 eV) (Fig. ). This substantial difference in energy disparity illustrates how the topology of woven structures can greatly reinforce the mechanical properties of individual molecular chains. (Corresponding changes of these weaves upon stretching at different ratios were illustrated in Supplementary Information, Figure -27) Additionally, during the stretching test, while the bond length in the free chain undergoes relatively uniform changes, in the weaves, it is concentrated in the entangled area (Supplementary Information, Figure ). This observation again confirms that mechanical stress is primarily dissipated at the entanglements within the woven fabrics. Fig. | Total energy and charge density analysis of strands stretching process in different weaves using first-principles calculations. (a) Energy analysis of the stretching process on three weaves reveals distinct energy profiles. The plain weave (navy) exhibits a notably rapid increase in energy compared to the other two weaves at the same strain ratio, indicating its lowest flexibility due to the highest entanglement density and strongest interstrand weak interactions. Beyond a strain ratio of 1%, both the basket (pink) and mix weaves (green) demonstrate a similar energy trend. At a strain ratio of 9%, the strands reach a fully stretched conformation, with the total energy increase across the three weaves following this ranking: plain weave > mix weave > basket weave, reflecting a positive correlation with the number and density of entanglements and interstrand interactions; (b) Differential charge densities of contact field of plain weave in equilibrium state and strained by 9%. Shadow blue and green shades in the panels represent the loss and gain of electrons, respectively. Differential charge densities are visualized using isosurfaces of 0.0005 e/Bohr 3 , it is noteworthy that electrons migrate from the interlacing field to the contact field upon stretching; (c) Energy analysis of a single strand in the stretching process shows significantly lower energy changes compared to the weaves. Stretching induces energy changes in free individual strands that are approximately 20-30 times lower, averaging around 0.9 eV.