Remove Related Products from the Single Product Page for Products in a Specific Category

functions.php

<?php

add_action( 'wp', 'vn_remove_related_products' );

function vn_remove_related_products() {
  // replace 'accessories' with the slug for your product category
  if ( is_product() && has_term( 'accessories', 'product_cat' ) ) {
	remove_action( 'woocommerce_after_single_product_summary', 'woocommerce_output_related_products', 20 );
  }
}

Thanks much for that snippet!