Closure lockdown assemblies and methods utilizing active materials

A reversible lockdown system for a closure hingeably attached to a vehicle body, comprising:

• a sensor that generates a signal based on pre-impact or impact information;
• a controller disposed to receive the sensor signal and deliver an activation signal to at least one device in operative communication with the closure and the vehicle body, wherein the at least one device comprises an active material disposed in operative communication with the hood and the vehicle body, wherein the active material comprises a shape memory alloy, a magnetic shape memory alloy, a shape memory polymer, a magnetorheological fluid, an electroactive polymer, a magnetorheological elastomer, an electrorheological fluid, a piezoelectric material, or combinations comprising at least one of the foregoing active materials, and wherein the activation signal effectuates a change in a shape, dimension, and/or flexural modulus property of the active material, wherein the change in the shape, dimension, and/or flexural modulus of the active material locks down or releases the closure from the vehicle.

A method for selectively stiffening a closure hingeably attached to a vehicle body, the method comprising:

• generating an activation signal, wherein generating the activation signal first comprises sensing and/or presensing an impact event;
• and
• activating at least one device in response to the activation signal, wherein the at least one device comprises an active material in operable communication with a closure and vehicle body, wherein the active material changes a shape, a dimension, or flexural modulus property of the active material upon receipt of the activation signal and stiffens an interface between the closure and the vehicle body.

In combination with a vehicle and a closure, one or more lockdown regions disposed between the closure and the vehicle body, the one or more lockdown regions comprising:

• a device comprising an active material disposed in operative communication with the closure and the vehicle body, wherein the active material comprises a shape memory polymer, a magnetorheological fluid, an electroactive polymer, a magnetorheological elastomer, an electrorheological fluid, a piezoelectric material, or combinations comprising at least one of the foregoing active materials;
• and
• an activation device coupled to the active material, the activation device being operable to selectively provide an activation signal to the active material and effectuate a change in a dimension, a shape, and/or a flexural modulus property of the active material, wherein the change in the dimension, a shape, and/or flexural modulus of the active material locks down or releases the closure from the vehicle.