var app = angular.module('plunker', ['ngMaterial']);

app.controller('MainCtrl', function($scope) {
  
  $scope.impacts = {
    availableImpacts: [{
      id: '1',
      name: 'name1'
    }, {
      id: '2',
      name: 'name2'
    }, {
      id: '3',
      name: 'name3'
    }],
  };

  console.log($scope.selectedImpact);
  
});
<!DOCTYPE html>
<html ng-app="plunker">

<head>
  <meta charset="utf-8" />
  <title>AngularJS Plunker</title>
  <link rel="stylesheet" href="https://material.angularjs.org/1.0.6/docs.css" />
  <!-- Angular Material CSS using GitCDN to load directly from `bower-material/master` -->
  <link rel="stylesheet" href="https://gitcdn.link/repo/angular/bower-material/master/angular-material.css">
  <!-- Angular Material Dependencies -->
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular-animate.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular-aria.js"></script>

  <!-- Angular Material Javascript using GitCDN to load directly from `bower-material/master` -->
  <script src="https://gitcdn.link/repo/angular/bower-material/master/angular-material.js"></script>
  <script src="app.js"></script>
</head>

<body ng-controller="MainCtrl">
  <md-input-container>
     <label>impact</label>
    <md-select ng-model="selectedImpact">
      <md-option  ng-repeat="impact in impacts.availableImpacts" value="{{impact.name}}">
        {{impact.name}}
      </md-option>
    </md-select>
  </md-input-container>
</body>

</html>
/* Put your css in here */