Strengthening and customization of zinc facade panels using single point incremental forming - thesis research

Strengthening and customization of zinc facade panels using

single point incremental formingGert-Willem Van Gompel

Master in Engineering: Architecture

KU Leuven Department of Architecture Department of Mechanical EngineeringPromotor: Vande Moere AndrewAssessors: Duflou Joost Cannaerts Corneel Lambaerts Marc Mattelaer Matthias Vanhove HansVMZINC: Ecker Bruno Lyonnet Pierre

Introduct ion

Context

Digital Fabrication

SPIF

Studies

Study 1: Toolpath generation

Study 2: Toolpath patterns

Study 3: Direct programming

Study 4: Form finding - simulated

Study 5: Form finding - measured

Depressur izat ion tests

First test campaign

Second test campaign

Evaluation of the results

Conclusion

Gert-Willem Van GompelMaster in Engineering: Architecture (2015 - 2016)

KU Leuven Department of Architecture Department of Mechanical Engineering

Promotor: Vande Moere AndrewAssessors: DuflouJoost Cannaerts Corneel Lambaerts Marc Mattelaer Matthias Vanhove HansVMZINC: Ecker Bruno Lyonnet Pierre

Introduction

Title:

Strengthening and customization of zinc facade panels using single point incremental forming (SPIF)

Research question:

This thesis investigates how SPIF can make a useful contribution in transforming metal façade cassettes, by exploring its strengthening capacities simultaneously with its ability to fabricate elements with a customized aesthetic.

How?

Literature - context digital fabrication SPIFInvestigation of the toolpath generation the form finding hypothesisFabrication with SPIFVerification with depressurization tests




Digital fabrication as a “missing link“ between design (left) and production (right).

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




http://www.digitaltrends.com/computing/best-desktop-3d-printers/

3D Printing as an example of digital fabrication.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




http://gramaziokohler.arch.ethz.ch/web/e/lehre/276.html

“Remote material deposition”, different approach of digital fabrication.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




computerization

computation

Instead of exactly translating a virtual model into reality, one can design through production. This can also be seen as the difference between computerisation and (material) computation.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




Two classification methods of existing digital production techniques. In the horizontal direction a technical distinction can be found (HauscHild & Karzel 2011), while the vertical separation represents a more fundamental theoretical difference.(Gramazio & KoHler 2014). The question mark in the table is where the scope of this thesis is situated.

Addin

gS

ubtr

acti

ng

Join

ing

Tran

sfor

min

g

Result determined by- Virtual model - Virtual model / toolpath

- Production technique- Material

Fig. 5 Top DSIF Method A with a forming tool and a support tool. Bottom DSIF Method B withtwo forming tools

40 A. Kalo and M. J. Newsum

?

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




SPIF

SPIF = Single Point Incremental Forming•sheet metal processing technique•without die•small batches & prototypes• relatively cheap & fast



Figure 17: Single Point Incremental Forming of a cone.

Figure 18: FLDo for different step sizes for AA 1050-0, with upper and lower bounds, with a 12 mm diameter tool [59].

Minor strain

Maj

or s

train

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4

1.2

1.0

0.8

0.6

0.4

0.2

0

1.4

1.6

1.8

Scattering band for mild steel (t=1.5 mm)

2.0

6 mm tool

10 mm tool

30 mm tool

31

42

2

3

4

1 x

x

x

x

Minor strain

Maj

or s

train

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4

1.2

1.0

0.8

0.6

0.4

0.2

0

1.4

1.6

1.8

Scattering band for mild steel (t=1.5 mm)

2.0

6 mm tool

10 mm tool

30 mm tool

31

42

2

3

4

1 x

x

x

x2

3

4

1 x

x

x

x

Figure 19: FLD for to = 1.5 mm DC04; influence of forming

tool size upon forming limits [60]. Graph points x1 to x4 correspond to positions on the sheet marked by x.

Kim & Park [70] focused their attention on the influence of anisotropy on formability. For this purpose, a set of measurements of the major and the minor strains were carried out both along the rolling direction (RD) and the transverse one (TD). The tests were developed for pyramid specimens with a varying tool diameter. The material was the aluminium alloy 1050-O, with E = 70GPa, σο = 33MPa, R0 = 0.51, R45 = 0.75, R90 = 0.48. They concluded that formability along the transverse direction is greater when small diameter tools are utilized, while along the rolling direction it is larger with large diameter tools. In order to fully understand the increase in formability with AISF, a simple FEM was developed by Micari et al. [59] and Bambach et al. [69]. They found that with decreasing step size, ∆z, the strain increments imposed at each loop decrease and any point is overlapped other ‘active loops’, while strains increase with increasing wall angle. Also, from a stress point of view, a negative mean stress distribution is observed under the tool and in the nearby elements; in this way, the tool action postpones ductile fractures during the process, until the tool is out of contact with the sheet. Finally, at decreasing ∆z the stress value along the wall decreases too, so that a higher deformation can be imposed without tears occurring. Nontraditional Forming Limit Diagrams Forming limit diagrams usually have the dashed V-shape shown as FLC in conventional forming in Figure 20. However, extensive research has shown that not only are much higher strains achieved in this process, but the Forming Limit Curve (FLC) in SPIF has a negative slope as shown in Figure 20 [32, 62]. In one case, the maximum forming strains [32] were actually much higher because the AA 1050-0 sheet used in the experiments had been etched with a grid causing stress concentrations and hence premature failure to occur. Young and Jeswiet [62] used more than one shape to develop a composite FLD for 1.21 mm thick AA 3003-0. They used five different shapes with varying angles, and convex and concave curves. The shapes were: a dome, a cone, a hyperbola, a pyramid and a shape with both compressive and tensile stresses. These all have their own FLD, and when all placed in one, common FLD, they represent most combinations of shape found in a part. An example of their work is shown Figure 21. The boundary for safe forming, without any tearing, is shown by the dashed red line. It can be seen that both Filice [32] and Young [62] have the same slope for the boundary and that very high strains were achieved. It can be seen that the non-traditional FLD’s being developed [32, 62] provide the designer with an additional method of judging if a design can be made in one pass with AISF.

εmin

-0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6

Maj

or s

train

,εm

ax1.00.90.80.70.60.50.40.30.20.1 FLC conventional forming

FLC incremental forming

εmin

-0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6-0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6

Maj

or s

train

,εm

ax1.00.90.80.70.60.50.40.30.20.1 FLC conventional forming

FLC incremental forming

Figure 20: FLC for 1.21 mm thick AA 1050-0 forming of

pyramids [32]. Both traditional and non-traditional curves.

UUppppeerr lliimmiitt

LLoowweerr lliimmiitt

Εmax, FLDo 3.5

Depth of step, ∆z, mm

0.5

1.5

2.5

0

1

2

3

0.00 1.00 2.00 3.00 4.00

points to generate new, virtual target geometry. This virtual part geometry forms the basis for the determination of an improved toolpath. Using a scale factor of 0.7 was found to provide optimal results for part made of DC04, 1.5 mm.

V shaped tub

Ambrogio et al. [106] use an in-process measurement system that allows the determination of deviation between the anticipated intermediate part geometry and the actually realized intermediate shape. Per layer (incremental toolpath contour) the observed deviations are measured to correct the toolpath geometry for the next contour.

Cone Cross Hexagon

The proposed system has been tested with a discrete point contact measurement system, used interactively, thus simulating the availability of real in-process measurement equipment. The toolpath optimization algorithm has been tested with pyramid part geometry. The author claims significant accuracy improvements. No quantitative output is however available to evaluate the achievable dimensional accuracy.

HyperbolaDome 5 lobe shape

5 EXAMPLES OF APPLICATIONS The major advantage of asymmetric incremental forming is it can be used to make asymmetric parts, quickly and economically, without using expensive dies. Shapes used to demonstrate the abilities of the process are shown in Table 8. Some of the shapes illustrated have been used to conduct springback experiments, and in determining the maximum draw angle φ, others are just for demonstration of process abilities. The asymmetric single and two point incremental forming processes are still in their infancy. Much research work remains to be done and to do this appropriate shapes are needed to develop: FLD’s, springback models and models to test accuracy. Standard shapes are used to determine what the draw angles should be for different materials and thickness. Standard shapes are needed to compare experimental results and for testing the process for maximum speeds of deformation. When testing materials for the maximum draw angle φ a truncated cone as shown in Figure 15 was agreed upon [59]. This shape has also been used by others [31, 32, 33, 59, 64, 66]. A pyramid shape has also been used on many occasions to demonstrate the asymmetric abilities of the new process plus it has become useful in determining the springback that occurs for different material thickness’ and for conducting pre and post process material tests [59, 64, 65, 67, 77]. Jadhav [100] has also used the pyramid to conduct studies of twisting in a shape once forming is completed. There is not agreement on which shape or shapes should be used to develop FLD’s for the new processes. Filice [32] and Hirt [78] have used a pyramid. Young is a proponent of using several shapes each of which has elements contained in most part shapes [62]. 5.1 Rapid Prototype Examples Making Rapid Prototypes, with sheet metal as the base material, giving a part that can be used directly in the function for which it is intended, is one of the major advantages of using this Incremental Forming process. The parts shown in table 9 are for designs that were made as Rapid Prototypes for the automotive industry. They are for the reflective surface of prototype headlights, for the first two cases. The third case is for a heat/noise shield, which is used over exhaust manifolds. Table 10 shows examples of rapid prototypes made for non-automotive applications. The first example is of a solar

Table 8: Shapes used to demonstrate the viability of the process and for experiments.

oven cavity for use in developing country applications. The last two are for the same manufacturer of custom motorbikes; the first part is for a motorbike seat and the second is part of a gas tank. 5.2 Custom manufacture of a solar oven The SPIF process has made it possible to manufacture an aluminum solar oven cavity, economically without dies. The ability to make a sheet metal cavity, inexpensively, has allowed designers of the solar oven to redesign other parts of a product, thereby reducing the cost and labour in making a solar oven. A solar oven has been designed for export to developing countries. Originally the oven cavity was made from fibreglass, and painted black. The major drawback, was the fibreglass wall was 7 mm thick, heavy, time consuming to build, and labour intensive. The possibility of using dies to form sheet metal into solar cooking cavities was investigated and found to be very expensive. This lead to considering SPIF of sheet metal as a method of manufacture. Figure 49 shows how the assembled solar oven works. The red shape is the part which is formed by SPIF. A three dimensional model was made in a Unigraphics environment and Figure 50 shows the model and increment details. The total depth of the model is 74 mm. The downward step for each pass was set up differently for the two sections shown; ∆z = 0.4 mm from A to B, and ∆z =0.3 mm from B to C. The method of programming included a z-level profile following part contour, which is available in Unigraphics, was used. Details of the process set-up in Unigraphics are:

Maximum drawing angle: set to 65o, everywhere. Forming tool: 25.4 mm diameter, highly polished. Forming speed (feedrate): 1125 mm/min. Additional note: the forming tool rotates freely, and is not matched to the machine feedrate. 1.3 mm thick AA 8008-0 Aluminum.

The final, successful result is shown in table 10. Although the customer was unconcerned by springback, the cross-section was measured to find out how much springback actually occurred; see Figures 47 and 51.

Truncated pyramid

Faceted cone

Multi-shaped surface

Kalo, A., & Newsum, M. J. (2014). An Investigation of Robotic Incremental Sheet Metal Forming as a Method for Prototyping Parametric Architectural Skins. Robotic Fabrication in Architecture, Art and Design 2014, 33-49.

Jeswiet, J., Micari, F., Hirt, G., Bramley, A., Duflou, J., & Allwood, J. (2005). Asymmetric single point incremental forming of sheet metal. Cirp Annals-Manu-facturing Technology, 54(2), 623-649.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




SPIF

overall geometry curvature. The parts were spot welded together at the valleys andpeaks to create the self-supporting system (Fig. 8).

Another system was developed as a series of panels that have a global pattern ofribs which structure the edge and register the panels through overlapping con-nections. The central protrusions are formed as undercuts (easily achievable withmulti-axis forming) and orient the panel on a clipping system (Fig. 9). Thebespoke ribs, bumps, and surface textures aren’t formed solely on their aestheticvalue, but are born out of the conflation of design, fabrication process, and con-nection detailing. In addition, they deliver a performative relationship between thepanels and the materials formed (Hensel and Menges 2009). The aim is to avoidany kind of superficial patterning and allow for the expression of the performativeaspects embedded in the panels. These patterns were a result of trying to find adesign solution to minimize springback after trimming and utilized as indexingguides. A series of different structural patterns based on surface curvature analysiswere developed and tested. Laser scanned models of the ‘ribbed’ trimmed panelsshow a 75 % improvement in the overall geometry when compared with untreatedpanels. The amount of deviation drops from 73 mm on the original un-texturedpanel to 15 mm after introducing the structuring textures (Fig. 10).

Another area of added functionality was geared towards developing panels thatcollect and direct water. The Namib Desert Darkling Beetle has the unique abilityto ‘fog-bask’, a strategy utilized by the beetle to use its own body as fog collectors(Nørgaard and Marie 2010). Similar to the Namib Desert Darkling Beetles’ elytra,the panels are designed to have areas coated with a hydrophilic, water attracting,film and other areas with a hydrophobic, water repellent, film.

The implication is creating a building facade or roof systems that employ such atechnique to efficiently collect water from fog. For this strategy, ‘micro bumps’ areadded to the formed component to increase the surface area. The hydrophilic peaksof the bumps allow the water to gather and then drip across the hydrophobic onceit reaches its capacity. The surface texture not only structures the panel locally, butalso become guiding flow-lines for shedding water in a controlled way. Thissystem has been tested on small samples and is yet to be developed into a largeraggregated system (Fig. 11).

Fig. 8 Aggregation of self-supporting thickened porous skin

An Investigation of Robotic Incremental Sheet Metal Forming 43

Kalo, A., & Newsum, M. J. (2014). An Investigation of Robotic Incremental Sheet Metal Forming as a Method for Prototyping Parametric Architectural Skins. Robotic Fabrication in Architecture, Art and Design 2014, 33-49.

Bailly, D., Bambach, M., Hirt, G., Pofahl, T., Della Puppa, G., & Trautz, M. (2015). Flexible manufacturing of double-curved sheet metal panels for the realization of self-supporting freeform structures. Key Engineering Materials, 639, 41-48.

Nicholas, P., Stasiuk, D., Nørgaard, E. C., Hutchinson, C., & Ramsgaard Thomsen, M. (2015). A Multiscale Adaptive Mesh Refinement Approach to Architectured Steel Specification in the Design of a Frameless Stressed Skin Structure. Modelling Behaviour, 17-34.

Architectural applications with assymetric incremental sheet forming.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Left: Contours with continuous step-down. Right: Contours with more continuous on-surface distance.

Left: Contour toolpath with abrupt transition.Right: Spiral toolpath.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Formation of the line pattern. Left: regular spiral toolpath with circles and interpolation points. Right: Pattern toolpath by interpolating between points on circles.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Six variations of toolpath patterns.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Robot setup.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Six variations of toolpath patterns produced with SPIF.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Six variations of toolpath patterns produced with SPIF.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





0 50 100 150 2000,0

0,5

1,0

1,5

2,0

Toolpath length (m)

Spri

ng b

ack

(mm

)

2

1 3

5

6

4

1

2

3

4

5

6

Smaller step-down toolpaths (5 and 6) showed a higher springback value.The curled toolpath with a step-down of 3 mm (4) resulted in the lowest springback, while still reducing the toolpath length compared to the small step-down toolpaths.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





8

1

2

3

4

57

6

Top and side view of the X-type toolpath. In the top view the locations of the first eight interpolation coordinates are illustrated.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Photographs from an X-type variant produced with SPIF on a sheet of zinc.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Addin

gS

ubtr

acti

ng

Join

ing

Tran

sfor

min

g

Result determined by- Virtual model - Virtual model / toolpath

- Production technique- Material



Fundamentally different approach of incremental sheet forming, corresponding with the ideas of direct programming and material computation.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Rendering of a project design from the architectural office DMOA, served as the conceptual idea for the Square-type toolpath.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





1 2

34

5 6

78

910

11 12

1314

15 1617

18 19

2021

22 23

2425

2627

28 29

3031

Top and side view of the Square-type toolpath and cassette. In the top view the locations of the first 31 coordinates are illustrated.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





0,04% (b)

0,31% (b)

3,67% (b)

100%

0.001% (a)

0.06% (a)

100%

a.

b.

c.

d.

e.

f.

g.

The deflection patterns of different geometries simulated and compared to each other. The panels are subjected to a virtual distributed wind load. Shapes a,b and c are lineary restrained at the four edges. Shapes d - g are restrained at the corners. From left to right: side view - perspective view - top view with the corresponding deflection pattern.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




Study 5: Form finding - measuredNom du système : Cassette Chicago QZ n° R&D : 09007 RE 023 - 2

Caractéristiques du montage ( dim. des élts, entraxe, fix. ) :

Cassette horizontale Zinc+ l = 585 mmFixation par Vis Ef Vis = 535 mm L = 585 mm

Profondeur 40 mm ep = 1,02 mmEmboîtement renforcé

Vis SFS 5,5 x 37Fixation sur 2 Profils Oméga Alu 25/10e

6 comparateurs

Déboutonnage de la vis

Forte déformation dans l'angle de la cassette

Nom des opérateurs : L. Rannou Date & Signature : 27/04/2010J. Caron

ESSAI DEPRESSION - FICHE DE RESULTAT ( n° )

On localisera les points de mesure ( P1…P9 ), les déformations et les points de ruine

MONTAGE K7 Chicago

600

600

600

535

A (0,0)

y

Vis

P3

P2

P1

P5

P4

P6

Rails Alu

Cassette Chicago

Abstract from depressurization test report of the cassette of type Chicago showing the alignment of the cassettes and the location of the sensors.

Measured deformation data will be used. The data are derived from previous depressurization tests performed by VMZINC.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





0 Pa

1500 Pa

3000 Pa

250 Pa

1750 Pa

3250 Pa

500 Pa

2000 Pa

3500 Pa

750 Pa

2250 Pa

3750 Pa

1000 Pa

2500 Pa

4000 Pa

1250 Pa

2750 Pa

4500 Pa

Graphical representation of the deformation shape after interpolation between the measured local deflection at each stage of the test.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




First test campaign

S30 C30 C30

C30RS60

Geometry Toolpath Pattern parameters Element

Type Form Depth

(mm)

Step-down (mm)

Scalp

(mm)

Length (m)

Pattern type

Points Space(mm)

Radius (mm)

Spring back (mm)

Material Dimensions (mm)

Thickness (mm)

S30 FF. 30 1 10 47,7 Straight 1 / / 1,2 Zinc Natural Cassette 585 x 585 0,8

C30 FF. 30 1 35 77 Curl 3 35 25 0,4 Zinc Natural Cassette 585 x 585 0,8

S60 FF. 60 1 10 90,2 Straight 1 / / 0,9 Zinc Natural Cassette 585 x 585 0,8

R Flat 0 / / / / / / / / Zinc Natural Cassette 585 x 585 1

Cassettes of the type VMZ Mozaik transformed with SPIF, mounted on a wall before testing.

The first test campaign consisted of the types S30, C30, S60, R.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




First test campaign

The ‘C30’ and ‘S60’ type performed the best. Additionally, none of the ‘C30’ types did tear during the test procedure.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




First test campaign

Both the ‘S30’ (left) and ‘S60’ type (right) showed premature damaging, which initiated the rupturing during the test.

Photographs before and after test procedure:

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





The second test campaign consisted of types X, Square and R (0,8 mm) (not included in thesis text)

This test campaign lasted longer than thee previous tests. No tearing occured at the X-type cassettes. The Square-type cassettes encountered tearing out of the screws.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





The overall impression is that the X-type performed the best at all aspects.Note: ‘X’ and ‘Square’ types are produced on cassettes with thickness 1 mm. ‘S30’, ‘C30’ and ‘S60’ are produced on cassettes with thickness 0,8 mm.

(5)(6) (4) (3) (2) (1)

1/100

1/50

(X, Square and R08 not included in thesis text)

Pressure (Pa) at deflection of Deflection (mm) at pressure of Tearing occurred?

Test ended at (Pa)Type 1/100 1/50 3500 Pa 4750 Pa 5250 Pa

S30 3500 (4) / 25 / / yes (2 cassettes) 3831

C30 / / 23 / / no 3831

S60 4600 (2) / 19 33 / yes (2 cassettes) 5243

R1 2010 (5) 4600 27 38 / yes (2 cassettes) 5243

X 4850 (1) / 20 31 37 no 5588

Square 4300 (3) 5100 24 36 44 yes (1 cassette) 5588

R08 500 (6) 2500 38 / / yes 4211

Comparison of some critical values

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion





Pressure (Pa) at deflection of Deflection (mm) at pressure of Tearing occurred?

Test ended at (Pa)Type 1/100 1/50 3500 Pa 4750 Pa 5250 Pa

S30 3500 (4) / 25 / / yes (2 cassettes) 3831

C30 / / 23 / / no 3831

S60 4600 (2) / 19 33 / yes (2 cassettes) 5243

R1 2010 (5) 4600 27 38 / yes (2 cassettes) 5243

X 4850 (1) / 20 31 37 no 5588

Square 4300 (3) 5100 24 36 44 yes (1 cassette) 5588

R08 500 (6) 2500 38 / / yes 4211

Comparison of some critical values

The overall impression is that the X-type performed the best at all aspects.Note: ‘X’ and ‘Square’ types are produced on cassettes with thickness 1 mm. ‘S30’, ‘C30’ and ‘S60’ are produced on cassettes with thickness 0,8 mm.

1/100

1/50

(X, Square and R08 not included in thesis text)

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




ConclusionEconomic

The total cost of such facade panels is influenced by

► production time - toolpath length; ► material usage - sheet thickness - strength;

and can be achieved by

► modifying the geometry; ► increasing the step-down; ► using alternative toolpath generation methods.

1,0 1,5 2,0 2,5 3,00

2

4

6

8

10

12

14

16

0,0 0,5 1,0 1,5 2,0 2,5 3,00

20

40

60

80

100

120

140

160

Step down (mm)

Tool

path

leng

th (m

)

Step down (mm)

Tool

path

leng

th (m

)

The correlation between the step-down and the toolpath length (for a shallowly curved part of 300 mm x 300 mm and with a depth of 30 mm).

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




ConclusionStructural

Structural performance is increased by

► applying a deeper geometry; ► using a specific toolpath pattern (increased surface roughness).

The curled toolpath pattern showed

► (after SPIF) lower springback values; ► (before test) no premature damaging at the corners of the cassettes; ► (during test) lower deformation; ► (after test) no damage at all.

Comparison of the overall performance of panels with different ribbing systems (Kalo & Newsum 2014, 45). These superficial ribbing systems showed to reduce the springback after trimming.

Similar findings:

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




ConclusionArchitectural

Performance-oriented design at 3 scales:

►pattern - toolpath generation ► form - form finding, overall geometry ► facade

Design at each level is driven by functional or structural requirements.

Different explorations of the surface envelope of the Piraeus tower in Athens, based on solar exposure analysis (HeNsel & meNGes 2009, 1).

Performance-oriented design of a facade:

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion




Conclusion

One can conclude that the

►economic, ►structural, ►and architectural

aspects of this topic have shown to be strongly interwoven with each other.

Future research might focus on

► the structural influence of superficial patterning and toolpath patterns; ►and the forming limitations of larger-step-down incremental forming;

in order to ultimately introduce SPIF in architectural practice, as an economically feasible way of transforming metal facade cassettes. This way, every project can be given a unique identity without any effort.

Introduct ion

Context

Digital Fabrication

SPIF

Studies







First test campaign



Conclusion

Acknowledgments:Department of Architecture

► Andrew Vande Moere ► Corneel Cannaerts

Department of Mechanical Engineering ► Joost Duflou ► Marc Lambaerts ► Hans Vanhove

DMOA architects ► Matthias Mattelaer

VMZINC ► Bruno Ecker ► Pierre Lyonnet