Option Explicit
Sub ConcatenationFeuilles()
Dim i As Long
Dim T() As Variant
Application.ScreenUpdating = False
ShConcat.Cells.Clear
For i = 1 To Sheets.Count
If Sheets(i).Name <> ShConcat.Name And IsNumeric(Sheets(i).Name) Then
With Sheets(i)
T = .Range("A7:F14").Value
ShConcat.Range("A" & Rows.Count).End(xlUp).Offset(1).Resize(UBound(T, 1), UBound(T, 2)) = T
End With
End If
Next i
Erase T
Application.ScreenUpdating = True
End Sub