assign new related product in bundled product magento

$param = array(
           $productid=>array(
                  'position'=>0
            ),
            $productid=>array(
                  'position'=>0
            ));

$related_product = $product->getRelatedProductCollection();




foreach($related_product as $rproduct){
$rlateproduct = Mage::getModel('catalog/product')->load($rproduct->getId());
$data[$rlateproduct->getId()] = array('position'=>0);

}



if($data != ""){
$result = $param + $data;
}
else{
$result = $param;
}




$product->setRelatedLinkData($result);
$product->save();