Newdatabase option is not available in sql server management studio 2014 I connect to analysis server using windows authentication. But I can't create the new database.
For some reason, SSMS doesn't provide this New Database menu option for SSAS Tabular. But you can easily create a new empty or shell database with the following XMLA script. Just click the XMLA button in the toolbar and then paste in the following. Edit the ID and Name property to the desired database name. And edit the DOMAIN\GroupName to set the group that has admin permission. This will allow members of that group to deploy over this database without being SSAS admins for the whole instance.

The following script is for SSAS 2012 SP1 or 2014 Tabular models:

&lt;Create xmlns="http://schemas.microsoft.com/analysisservices/2003/engine"&gt;
    &lt;ObjectDefinition&gt;
        &lt;Database xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ddl2="http://schemas.microsoft.com/analysisservices/2003/engine/2" xmlns:ddl2_2="http://schemas.microsoft.com/analysisservices/2003/engine/2/2" xmlns:ddl100_100="http://schemas.microsoft.com/analysisservices/2008/engine/100/100" xmlns:ddl200="http://schemas.microsoft.com/analysisservices/2010/engine/200" xmlns:ddl200_200="http://schemas.microsoft.com/analysisservices/2010/engine/200/200" xmlns:ddl300="http://schemas.microsoft.com/analysisservices/2011/engine/300" xmlns:ddl300_300="http://schemas.microsoft.com/analysisservices/2011/engine/300/300" xmlns:ddl400="http://schemas.microsoft.com/analysisservices/2012/engine/400" xmlns:ddl400_400="http://schemas.microsoft.com/analysisservices/2012/engine/400/400"&gt;
            &lt;ID&gt;ShellDatabase&lt;/ID&gt;
            &lt;Name&gt;ShellDatabase&lt;/Name&gt;
            &lt;ddl200:CompatibilityLevel&gt;1103&lt;/ddl200:CompatibilityLevel&gt;
            &lt;ddl200_200:StorageEngineUsed&gt;InMemory&lt;/ddl200_200:StorageEngineUsed&gt;
            &lt;Language&gt;1033&lt;/Language&gt;
            &lt;Collation&gt;Latin1_General_CI_AS&lt;/Collation&gt;
            &lt;DataSourceImpersonationInfo&gt;
                &lt;ImpersonationMode&gt;Default&lt;/ImpersonationMode&gt;
            &lt;/DataSourceImpersonationInfo&gt;
            &lt;Roles&gt;
                &lt;Role&gt;
                    &lt;ID&gt;Role&lt;/ID&gt;
                    &lt;Name&gt;Administrators&lt;/Name&gt;
                    &lt;Members&gt;
                        &lt;Member&gt;
                            &lt;Name&gt;DOMAIN\GroupName&lt;/Name&gt;
                        &lt;/Member&gt;
                    &lt;/Members&gt;
                &lt;/Role&gt;
            &lt;/Roles&gt;
            &lt;DatabasePermissions&gt;
                &lt;DatabasePermission&gt;
                    &lt;ID&gt;DatabasePermission&lt;/ID&gt;
                    &lt;Name&gt;DatabasePermission&lt;/Name&gt;
                    &lt;RoleID&gt;Role&lt;/RoleID&gt;
                    &lt;Process&gt;true&lt;/Process&gt;
                    &lt;Read&gt;Allowed&lt;/Read&gt;
                    &lt;Administer&gt;true&lt;/Administer&gt;
                &lt;/DatabasePermission&gt;
            &lt;/DatabasePermissions&gt;
        &lt;/Database&gt;
    &lt;/ObjectDefinition&gt;
&lt;/Create&gt;


And for SQL 2016 Tabular models using the latest 1200 compatibility level, use the following script. Just change the name to the desired database name and the DOMAIN\GroupName to your administrators group.

{
  "create": {
    "database": {
      "name": "ShellDatabase",
      "compatibilityLevel": 1200,
      "model": {
        "culture": "en-US",
        "roles": [
          {
            "name": "Admins",
            "modelPermission": "administrator",
            "members": [
              {
                "memberName": "DOMAIN\\GroupName"
              }
            ]
          }
        ]
      }
    }
  }
}