tag:blogger.com,1999:blog-72899908692807606852024-08-30T19:28:17.729-07:00Materials which expand when force is exerted on them and vice versaUnknownnoreply@blogger.comBlogger1125tag:blogger.com,1999:blog-7289990869280760685.post-91851673432800173812012-03-27T09:38:00.003-07:002012-03-27T09:55:47.094-07:00<div dir="ltr" style="text-align: left;" trbidi="on"> <div style="text-align: justify;"> <span style="font-family: Georgia, 'Times New Roman', serif; font-size: 12pt; line-height: 150%;">In recent years, enhancements to mechanical properties such as low velocity impact resistance &nbsp;and sound absorption have driven the research into fabrication and testing of auxetic materials.</span></div> <div class="MsoNormal" style="line-height: 150%;"> <div style="text-align: justify;"> <br /></div> </div> <div class="MsoNormal" style="line-height: 150%;"> <div style="text-align: justify;"> <span style="font-family: Georgia, 'Times New Roman', serif;"><span style="font-size: 12pt; line-height: 150%;">Auxetic materials are those which exhibit a negative Poisson’s ratio, </span><span style="font-size: 12pt; line-height: 150%;">n</span></span><span style="font-size: 12pt; line-height: 150%;"><span style="font-family: Georgia, 'Times New Roman', serif;">, which has been known in highly anisotropic media such as pyrite crystals since the 1920s. Milton, in 1992, calculated Poisson’s ratios of close to −1 in composite materials and since then a lot of work has reflected that it is possible to engineer a negative Poisson’s ratio in either the in-plane or through thickness direction.&nbsp;</span><span style="font-family: Arial, sans-serif;"><o:p></o:p></span></span></div> </div> <div style="text-align: justify;"> <br /></div> </div>Unknownnoreply@blogger.com0