AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

AMB2022-06 Benchmark Measurements and Challenge Problems

Last updated on 5/6/2022

Modelers are invited to submit simulation results for any number of challenges they like before the 

deadline of 23:59 (ET) on July 15, 2022. Instructions for how submissions are to be formatted are 

included in this document and simulation results may be submitted here . A Q&A webinar was held on 

May 6 and a recording of the presentations and an FAQ will be posted shortly. Additional information 

may become available later so updated versions of this document may be posted. Please check back 

occasionally.

All evaluations of submitted modeling results will be conducted by the AM-Bench 2022 organizing 

committee. Award plaques will be awarded at the discretion of the organizing committee. Because 

some participants may not be able to share proprietary details of the modeling approaches used, we are 

not requiring such details. However, whenever possible we strongly encourage participants to include 

with their submissions a .pdf document describing the modeling approaches, physical parameters, and 

assumptions used for the submitted simulations.

Please note that the challenge problems typically reflect only a small part of the validation 

measurement data provided by AM Bench for each set of benchmarks. The Measurement Description 

section, below, describes the full range of measurements conducted.

AMB2022-06: Thermoplastic material extrusion of polycarbonate test objects. Detailed descriptions are 

found below, and simulation results may be submitted here.

Challenges

● Road width (CHAL-AMB2022-06-EW): The maximum and minimum horizontal width of a singleprinted road. [scalars]

● Road Dimensionless Cross-Section (CHAL-AMB2022-06-DCS): Shape of the cross-section of a 

single road. The submissions will be scaled to match benchmark results. [2D area or perimeter

submitted as a bitmap image].

● Road Cross-Section (CHAL-AMB2022-06-CS): Shape of the cross-section. The submissions will 

not be scaled, must be dimensionally accurate. [2D area or perimeter submitted as a bitmap 

image].

Overview and Basic Objectives 2

Sample and extrusion processing 2

Measurement descriptions 5

Benchmark Challenge Problems 6
AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

Description and Links to Associated Data 7

References 7

Overview and Basic Objectives

The goal of the Thermoplastic Material Extrusion AM-Bench 2022-06 Benchmark Challenge is to 

accurately model the relationship between material properties (viscoelasticity) and print parameters 

(temperature, rate, nozzle diameter) and the resultant single-layer part dimension (i.e. width and crosssection) of an amorphous polymer. The primary objectives are to predict the width and cross-sectional 

shape of the printed material. The improved prediction of these relations will foster enhanced tool path 

part performance.

Experimental data for model calibration and challenge comparison are provided through material 

characterization (linear rheology) and system calibration (extrudate temperature). These experiments 

were carried out at the National Institute of Standards and Technology. Released calibration 

measurements were performed on two commercial filaments. Most of the calibration data are included 

below and additional data will be available for download shortly.

Sample and extrusion processing

Polymer

Commercial bisphenol-A-polycarbonate filament (Tg = 154 °C, Mn = 30.1 kg/mol, Mw = 68.7 

kg/mol) was used to prepare the samples. The filament is nominally 2.85 mm, with actual 

dimensions of 2.84 mm ± 0.03 mm. 

Figure 1: Linear rheology of polycarbonate
AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

Figure 2: Shift factors for polycarbonate

Printing

The sample is two layers high, one extrudate wide, and 150 mm long, with one layer high, 1 cm 

by 1 cm adhesion feet at either end. The polycarbonate filament was dried at 120 °C under 

vacuum for 12 h. The build plate is borosilicate glass painted with a thin layer of polyvinyl 

alcohol water-soluble adhesive. The printing system was preheated for 10 min. The extruder 

nozzle was purged prior to every print. The sample order was randomized. The bed set point 

was 145 °C with a measured surface temperature of 118.3 °C ± 0.1 °C. Extrusion setpoints are 

240 °C, 260 °C, 280 °C, 300 °C, 320 °C, and 340 °C. However, the actual extrusion temperature 

is 50 °C to 60 °C lower (updated extrusion temperatures to follow). Print head translation 

speeds are 10 mm/s and 100 mm/s. The nozzle diameter is 0.51 mm. The hot end is Al, 1 cm in 

length with a 3.1 mm internal diameter which extends into the nozzle which has a short 45° 

taper ending in the 0.51 mm nozzle opening, see Figure 3. (nozzle specs, A2 hardened tool 

steel, hardness 56RC, thermal conductivity 27 W/m-K).
AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

Figure 3: Nozzle drawing

The first layer is printed with square, 1 cm by 1cm “feet” at each end to help with adhesion. The 

feet are always printed at vx,y = 20 mm/s, additionally, all travel moves are the same. The first 

layer printed between the “feet” is printed at the “challenge” speed, as is the 2nd layer. See 

Figure 5 for an example of the printed sample. The timing for each layer section of the is 

provided in Table 1. 

Table 1: Printing times for each section of the sample.

vx,y (mm/s) Start foot 

time (s)

First layer 

time (s)

Back foot 

time (s)

Travel time (s) Second layer 

time (s)

10 23.25 11.95 23.25 3.91 15.0

30 23.25 3.98 23.25 3.91 5.0

100 23.25 1.19 23.25 3.91 1.5
AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

Figure 4: Illustration of sample printing.

Figure 5: Illustration of the printed sample. 

Measurement descriptions

Widths and cross-sections are characterized by x-ray computer tomography. Cross-sections 

from x-ray computer tomography will average approximately 1 cm of extrudate or road length 

and provide a cross-section with approximately 2 μm voxels, which results in 4 μm to 6 μm 

cross-section “pixels”.
AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

Benchmark Challenge Problems

CHAL-AMB2022-06-EW

In the extrudate width (EW) challenge we ask the modeler to predict the maximum (extrudate) 

and minimum (interface) width of the extruded layer parallel to the build plate and normal to the 

print direction. See Figure 6 for an illustration of the widths of interest.

Figure 6: Illustration of the two-layer sample with extrudate and interface widths.

CHAL-AMB2022-06-DCS

In the dimensionless cross-section (DCS) challenge we ask the modeler to predict the crosssection shape of the 2nd layer up to the interface or both layers, but not necessarily match the 

exact dimension. The prediction will be scaled to match the measured cross-section. See Figure 

7 for an illustration of the perimeters of interest.

Figure 7: Illustration of a) Layer 2 cross-section perimeter (black line) and b) Layer 1 and Layer 

2 cross-section perimeter (black line)
AMB2022-06 Benchmark Measurements and Challenge Problems – PDF Copy

CHAL-AMB2022-06-CS

In the cross-section (CS) challenge we ask the modeler to predict the exact cross-section shape 

of the 2nd layer up to the interface or both layers. See Figure 7 for an illustration of the 

perimeters of interest.

Description and Links to Associated Data

All data available to support the AMB2022-06 challenges are contained in the “Polymer 

properties and printer calibration (AMB2022-06)” dataset to be released shortly. 

New data files, updates, and/or changes to download URLs may be made periodically. Users 

should refer to the README text file which will record all updates. Additionally, the NIST Public 

Data Repository (PDR) undergoes frequent updates. If file downloads fail or are unavailable, 

users should wait several hours before contacting the technical support listed on the AMB2022-

06 dataset webpage.

References

N/A