Do not use fixed sizes like:
Height="554"
Let the TabControl fit the parent container content area.
UPDATE
I put your XAML (with the helix control removed) in my sample app and made a couple of tweaks and is now responsive, ie: no constraints:
<Grid RenderTransformOrigin="0.5,0.5" >
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<StackPanel x:Name="optionpanel" Background="#FFB3B3B3" Grid.Row="1" Grid.Column="0" Margin="5">
</StackPanel>
<StackPanel x:Name="settingpanel" Background="#FFB3B3B3" Grid.Row="1" Grid.Column="2" Margin="5" Width="300">
</StackPanel>
<StackPanel x:Name="footerpanel" Background="#FFB3B3B3" Grid.Row="2" Grid.ColumnSpan="3" Orientation="Vertical">
</StackPanel>
<StackPanel x:Name="headerpanel" Background="#143548" Grid.ColumnSpan="3" Grid.Row="0" Orientation="Vertical">
</StackPanel>
<Border x:Name="viewerPanel" Background="#b3b3b3" Grid.Row="1" Grid.Column="1" Margin="1,5.2,1,5">
<TabControl x:Name="viewtab" Background="#b3b3b3" BorderBrush="#FF123648" BorderThickness="2">
<TabItem Header="3D View">
<Grid Background="#b3b3b3" Margin="0,0,0.4,1">
<TextBlock Text="Content1"
HorizontalAlignment="Center"
VerticalAlignment="Center"/>
</Grid>
</TabItem>
<TabItem Header="Layer View">
<TextBlock Text="Content2"
HorizontalAlignment="Center"
VerticalAlignment="Center"/>
</TabItem>
</TabControl>
</Border>
</Grid>
Your main issue was the StackPanel. I changed it to a Border. Other edits were made to remove properties that are not required.