Results: Line clashing report

The line clashing report is a detailed tabular report of the line clashing events during a simulation. Line clashing reports are only available for time domain analyses.

To obtain a line clashing report:

The report is presented in a spreadsheet.

Contents of the line clashing report

The report consists of a summary table followed by a detailed table, as described below.

Summary table

The summary table lists all clash events for segments on the selected line. A clash event is deemed to start when a segment from the selected line first comes into contact with another line segment. We shall refer to the particular segment on the selected line as $S_1$. The clash event ends when $S_1$ is no longer in contact with any other line segments.

Note: During the course of a clash event the segment $S_1$ may be in contact with a number of different line segments from other lines, e.g. if the clash is a sliding contact. This is counted as a single clash event from the perspective of $S_1$.

For each clash event the following results are reported:

Event number

A number of clash events may occur during the simulation. Each event is given a number to identify it. This is useful when relating the summary results of a clash event to the detailed results.

Segment number and segment arc length

This identifies the segment S1 on the selected line.

Start time, end time and duration

The simulation time of the start and end of the clash event together with its duration.

Total impulse

The total impulse of the clash event.

Peak clash force

A scalar value reporting the greatest value of clash force achieved during the clash event. The clash force vector is monitored during each clash event and the greatest magnitude of this vector is reported.

Peak clash energy

A scalar value reporting the greatest value of clash energy achieved during the clash event.

Max penetration

At each time step we calculate the depth of penetration between the outer surfaces of segment $S_1$ and all other segments. Let $S_2$ be a segment on another line.

Let the radii of the two segments be $r_1$ and $r_2$ (as defined by the line type outer contact diameter). OrcaFlex calculates the shortest separation distance, $d$, between the centrelines of the two segments. The penetration of these two segments is defined to be $\left(r_1+r_2\right)–d$. The value reported as max penetration is the maximum value of penetration between segment $S_1$ and any other segment over the duration of the clash event.

Detailed table

The detailed table reports information about each individual contact between segment $S_1$ and another segment. If during the course of a clash event segment $S_1$ is in contact with a number of segments on other lines then the start time, end time and duration of each of those individual contacts is reported.

Contact velocity

The detailed table also includes the contact velocity for each individual contact. This is the normal component of relative velocity of the two contact points at the start of the time step during which the clash event started.