values modified by eloquent create() in laravel 5.2

I am creating a code by which i can replicate the multiple rows of table and its related tables.

I am able to replicate parent table successfully, but while replicating the contents of child table it is modifying the values which i am unable to figure it out.

my controller code is

public function copyshowtime($cinema_id,$show_date)
{
    $date=new Carbon($show_date);
    $current_show_date=$date->format('Y-m-d');
    $next_show_date=$date->addDay()->format('Y-m-d'); 

    $movieshowtime=Movies_showtimes::with('showdata')->where([['cinema_id','=',$cinema_id],['show_date','=',$current_show_date]])->get();

    foreach ($movieshowtime as $item) 
    {
        $item->show_date=$next_show_date;
        $item->show_id=NULL;
        $newshowtime=$item->replicate();
        $newshowtime->push();


        foreach ($item->showdata as $sd) 
        {

            $newshowdata = array(
                                    'showdata_id' => NULL,
                                    'show_id'=>$newshowtime->id,
                                    'category_id'=>$sd->category_id,
                                    'showdata_category'=>$sd->showdata_category,
                                    'showdata_rate'=>$sd->showdata_rate

                                );

           // print_r($newshowdata);
            Movies_showdata::create($newshowdata);
        }
    }
}

When I am printing the complete array its showing proper data which i am trying to insert ,check below

But after inserting it into table I see this data in table, the values of show_id and showdata_rate is getting zero value and other columns getting correct data inserted.

I am unable to figure out this problem as I am nowhere changing the data to zero before inserting it into table.

via Chebli Mohamed