Spar cap configuration for a jointed wind turbine blade

1. A jointed wind turbine rotor blade, comprising:

a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint line;

each of the first and second blade segments comprising opposite spar caps;

the first and second blade segments connected at the chord-wise joint line by internal joint structure configured between the first and second blade segments, the joint structure bonded to the opposite spar caps in at least the second blade segment;

the spar caps in the second blade segment comprising a first section with a first chord-wise width, the first section aligned in a span-wise direction with a second section having a second chord-wise width, the second section bonded directly to the joint structure;

the second chord-wise width being greater than the first chord-wise width;

the spar caps in the second blade segment comprising a constant reduced thickness portion along the second section extending span-wise to the chord-wise joint line as compared to a thickness along the first section; and

wherein the second section is bonded directly to the joint structure along the second chord-wise width and constant reduced thickness portion of the second section.

2. The jointed wind turbine rotor blade as in claim 1 , wherein the joint structure comprises a spar beam extending span-wise from first blade segment into a receiver configured in the second blade segment, the receiver comprising upper and lower spar surfaces bonded directly to the second section of the spar caps in the second blade segment.

3. The jointed wind turbine rotor blade as in claim 2 , wherein the upper and lower spar surfaces of the receiver comprise a chord-wise width corresponding to the second chord-wise width.

4. The jointed wind turbine rotor blade as in claim 1 , wherein the first blade segment is a tip-end blade segment and the second blade segment is a root-end blade segment.

5. The jointed wind turbine rotor blade as in claim 1 , further comprising a span-wise transition section in the spar caps in the second blade segment where the first chord-wise width increases gradually to the second chord-wise width.

6. The jointed wind turbine rotor blade as in claim 5 , wherein material used and a length of the span-wise transition section provide consistent structural properties to the spar cap along the span-wise transition section.

7. The jointed wind turbine rotor blade as in claim 5 , wherein structural properties of the spar cap vary along the span-wise transition section.

8. The jointed wind turbine rotor blade as in claim 1 , wherein the spar caps in the second blade segment are formed from a first material along the first section and are formed from a second material along the second section, and further comprising a scarf joint between the first material and the second material.

9. The jointed wind turbine rotor blade as in claim 8 , further comprising a span-wise transition section in the spar caps in the second blade segment where the first chord-wise width increases gradually to the second chord-wise width and a thickness of the spar caps decreases to the reduced thickness, the scarf joint disposed adjacent to the transition section.

10. The jointed wind turbine rotor blade as in claim 8 , wherein the first material comprises pultruded rods or plates, and the second material comprises unidirectional fiber plies.

11. The jointed wind turbine rotor blade as in claim 1 , wherein the spar caps in the first and second blade segments are formed from any one or combination of pultruded rods or plates or unidirectional fiber plies.

12. The jointed wind turbine rotor blade as in claim 1 , wherein the joint structure comprises a box-beam receiver with webs interconnecting the upper and lower surfaces.

13. The jointed wind turbine rotor blade as in claim 1 , wherein the second chord-wise width is constant where the second section of the spar caps in the second blade segment are bonded directly to the joint structure.

14. A wind turbine, comprising one or more of the jointed wind turbine blades according to claim 1 .

15. A jointed wind turbine rotor blade, comprising:

a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint line;

each of the first and second blade segments comprising opposite spar caps;

the first and second blade segments connected at the chord-wise joint line by internal joint structure configured between the first and second blade segments, the joint structure bonded to the opposite spar caps in at least the second blade segment;

the spar caps in the second blade segment comprising a first section with a first chord-wise width, the first section aligned in a span-wise direction with a second section having a second chord-wise width, the second section bonded directly to the joint structure;

the second chord-wise width being greater than the first chord-wise width;

wherein the spar caps in the second blade segment comprise a reduced thickness along the second section as compared to a thickness along the first section; and

further comprising a span-wise transition section in the spar caps in the second blade segment where the first chord-wise width increases gradually to the second chord-wise width and a thickness of the spar caps decreases from the thickness of the first section to the reduced thickness of the second section.