Tubular door reinforcement beam

1. A vehicle comprising:

a vehicle body defining an opening; and

a door configured to selectively open and close at least a portion of the opening, the door having:

an outer door panel;

an inner door panel attached to the outer door panel wherein a space is defined between the inner door panel and the outer door panel; and

a tubular reinforcement beam disposed in the space between the inner and outer door panels, attached to the door, and having varying material thicknesses;

wherein:

the tubular reinforcement beam has a first tubular portion having a first cross-section, a second tubular portion having a second cross-section, and a third tubular portion having a third cross-section;

in the first cross-section, the first tubular portion has a first material thickness;

in the second cross-section, the second tubular portion has a second material thickness;

in the third cross-section, the third tubular portion has a third material thickness; and

the first material thickness and the second material thickness are equivalent, and the third material thickness is different from the first and second material thicknesses;

the first, second, and third tubular portions are defined by a uniform inner diameter;

the first and second tubular portions have respective first and second inner diameters, and the third tubular portion is defined by a third inner diameter; and

the first inner diameter is equal to the second inner diameter and the third outer diameter is greater than each of the first and second outer diameters.

2. The vehicle of claim 1 , wherein the first, second, and third tubular portions are collectively defined by a single monolithic piece of material.

3. The vehicle of claim 1 , wherein:

the tubular reinforcement beam includes a first tube fixed inside a second tube;

the first tube defines the first and second tubular portions; and

the first and the second tubes define the third tubular portion.

4. The vehicle of claim 1 , wherein the first tubular portion is positioned at a first distal end of the reinforcement beam, the second tubular portion is positioned at a second distal end of the reinforcement beam, and the third tubular portion is positioned between the first and second distal ends of the reinforcement beam.

5. The vehicle of claim 4 , wherein the first and second distal ends are attached to the inner door panel.

6. The vehicle of claim 4 , wherein:

the reinforcement beam includes a first bracket at the first distal end of the beam and a second bracket at the second distal end of the beam;

the first distal end of the beam is attached to the first bracket and the first bracket is attached to the inner door panel; and

the second distal end of the beam is attached to the second bracket and the second bracket is attached to the inner door panel.

7. The vehicle of claim 6 , wherein the first and second brackets are attached to the inner door panel by at least one of a weld and a fastener.

8. The vehicle of claim 1 , wherein the third material thickness is greater than each of the first material thickness and the second material thickness.

9. A door for a vehicle comprising:

an outer door panel;

an inner door panel attached to the outer door panel, wherein a space is defined between the inner door panel and the outer door panel; and

a tubular reinforcement beam disposed in the space between the inner and outer door panels, attached to the door, and having varying material thicknesses

wherein:

the tubular reinforcement beam has a first tubular portion having a first cross-section, a second tubular portion having a second cross-section, and a third tubular portion having a third cross-section;

in the first cross-section, the first tubular portion has a first material thickness;

in the second cross-section, the second tubular portion has a second material thickness;

in the third cross-section, the third tubular portion has a third material thickness; and

the first material thickness and the second material thickness are equivalent, and the third material thickness is different from the first and second material thicknesses;

the first, second, and third tubular portions are defined by a uniform inner diameter;

the first and second tubular portions have respective first and second inner diameters, and the third tubular portion is defined by a third inner diameter; and

the first inner diameter is equal to the second inner diameter and the third outer diameter is greater than each of the first and second outer diameters.

10. The door of claim 9 , wherein the first, second, and third tubular portions are collectively defined by a single monolithic piece of steel.

11. The door of claim 9 , wherein:

the tubular reinforcement beam includes a first tube fixed inside a second tube;

the first tube defines the first and second tubular portions; and

the first and the second tubes define the third tubular portion.

12. The door of claim 9 , wherein the first tubular portion is positioned at a first distal end of the beam, the second tubular portion is positioned at a second distal end of the beam, and the third tubular portion is positioned between the first and second distal ends of the beam.

13. The door of claim 12 , wherein the first and second distal ends are attached to the inner door panel.

14. The door of claim 12 , wherein:

the reinforcement beam includes a first bracket at the first distal end of the beam and a second bracket at the second distal end of the beam;

the first distal end of the beam is attached to the first bracket and the first bracket is attached to the inner door panel; and

the second distal end of the beam is attached to the second bracket and the second bracket is attached to the inner door panel.

15. The door of claim 14 , wherein the first and second brackets are attached to the inner door panel by at least one of a weld and a fastener.

16. The door of claim 9 , wherein the third material thickness is greater than each of the first material thickness and the second material thickness.