Compute the K=-dQ/dx, R=-dQ/dv, M=-dQ/da Jacobians.

Implementation in a derived class should load the Jacobian matrices K, R, M in the structure 'm_jacobians'. Note the sign that is flipped because we assume equations are written with Q moved to left-hand side.

Parameters

state_x	state position to evaluate Jacobians
state_w	state speed to evaluate Jacobians

Implemented in chrono::ChLoadCustomMultiple, chrono::ChLoadCustom, chrono::ChLoadBodyInertia, chrono::ChLoad, and chrono::ChLoadBodyMesh.

Compute the generalized load(s).

A derived class should cache the resulting Q which is then used in LoadIntLoadResidual_F.

Parameters

state_x	state position to evaluate Q
state_w	state speed to evaluate Q

Implemented in chrono::fea::ChLoadNodeXYZRotBody, chrono::ChLoadNodeXYZBody, chrono::ChLoadBodyBody, chrono::ChLoadBodyInertia, chrono::ChLoad, chrono::ChLoadNodeXYZNodeXYZ, chrono::ChShaftsElasticGear, chrono::fea::ChLoadNodeXYZRotNodeXYZRot, chrono::ChLoadBodyTorque, chrono::ChLoadNodeXYZForce, chrono::ChLoadBodyForce, chrono::ChLoadBodyMesh, chrono::fea::ChLoadNodeXYZRot, and chrono::ChShaftsLoad.

Report if this is load is stiff.

If so, InjectKRMMatrices will provide the Jacobians of the load.

Implemented in chrono::fea::ChLoadNodeXYZRotBodyBushingGeneric, chrono::ChLoadBodyBodyBushingGeneric, chrono::fea::ChLoadNodeXYZRotBodyBushingSpherical, chrono::ChLoadNodeXYZBodyBushing, chrono::ChLoadBodyBodyBushingSpherical, chrono::ChLoadNodeXYZBodySpring, chrono::fea::ChLoadNodeXYZRotNodeXYZRotBushingGeneric, chrono::ChLoadNodeXYZNodeXYZBushing, chrono::ChLoadNodeXYZNodeXYZSpring, chrono::fea::ChLoadNodeXYZRotNodeXYZRotBushingSpherical, chrono::ChLoad, chrono::ChLoadNodeXYZNodeXYZ, chrono::ChShaftsElasticGear, chrono::ChLoadNodeXYZForceAbs, chrono::fea::ChLoadNodeXYZRotForceAbs, chrono::ChLoadNodeXYZForce, chrono::ChShaftsTorsionSpringDamper, chrono::ChLoadBodyMesh, and chrono::fea::ChLoadNodeXYZRot.

Number of coordinates in the interpolated field.

For example, 3 for a tetrahedron finite element or a cable, 1 for a thermal problem, etc.

Implemented in chrono::ChLoadCustomMultiple, chrono::ChLoadCustom, chrono::ChLoad, and chrono::ChLoadBodyMesh.

Add the lumped mass to an Md vector, representing a mass diagonal matrix.

In other words, perform the operation: Md += c*diag(M). Used by lumped explicit integrators. If mass lumping is impossible or approximate, adds scalar error to "err" parameter. If no mass matrix M is present (i.e., no inertial effects), implement as no-op.

Parameters

Md	result: Md vector, diagonal of the lumped mass matrix
err	result: not touched if lumping does not introduce errors
c	a scaling factor

Implemented in chrono::ChLoadBodyMesh, chrono::ChLoadCustomMultiple, chrono::ChLoadCustom, and chrono::ChLoad.

Add the internal loads Q (pasted at global offsets) into a global vector R, multiplied by a scaling factor c.

In other words, perform the operation: R += forces * c

Implemented in chrono::ChLoadCustomMultiple, chrono::ChLoadCustom, chrono::ChLoad, and chrono::ChLoadBodyMesh.

Increment a vector R with the matrix-vector product M*w, scaled by the factor c.

In other words, perform the operation: R += c*M*w (i.e., R += c*(-dQ/da)*w). If no mass matrix M is present (i.e., no inertial effects), implement as no-op.

Parameters

R	result: the R residual, R += c*M*v
w	the w vector
c	scaling factor

Implemented in chrono::ChLoadCustomMultiple, chrono::ChLoadCustom, chrono::ChLoad, chrono::ChLoadBodyMesh, and chrono::ChLoadBodyInertia.

Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects.

The resulting KRM blocks represent linear combinations of the K, R, and M matrices, with the specified coefficients Kfactor, Rfactor,and Mfactor, respectively.

Reimplemented in chrono::ChLoadBodyMesh.

Increment a packed state (e.g., as obtained by LoadGetStateBlock_x()) by a given packed state-delta.

Compute: x_new = x + dw. This method is used in calculating Jacobians with finite difference approximations (default implementations of ComputeJacobian).

Implemented in chrono::ChLoadCustomMultiple, chrono::ChLoadCustom, chrono::ChLoad, and chrono::ChLoadBodyMesh.

Update, called at least at each time step.

• It recomputes the generalized load Q vector(s)
• It recomputes the Jacobian matrices K,R,M in case of stiff load Q and Jacobians assumed evaluated at the current state. Jacobians are automatically allocated if needed.

Reimplemented from chrono::ChObj.

Reimplemented in chrono::ChLoadNodeXYZNodeXYZ, chrono::ChLoadNodeXYZForceAbs, chrono::fea::ChLoadNodeXYZRotForceAbs, chrono::ChLoadNodeXYZForce, and chrono::fea::ChLoadNodeXYZRot.