# Presentation: 050119

## Small Racetrack – Design, Mechanical Analysis and Fabrication 

**Srinivas Bhashyam**

- A. Zlobin

- 2/24/98

## Outline

**Mechanical Structure**
**Winding Assembly**
**Tooling **
**Magnetic/Mechanical Analysis Summary**
**Design Criteria**
**Shell Stresses/Strains**
**Coil Stresses/Displacements**
**Fabrication **
**Procurement Status**
**Fabrication scenarios and schedule**

_***Outline***_

- A. Zlobin

- 2/24/98

## Design Overview

**Mechanical Structure**
**Yoke, skin, pressure pad, keys – identical to LBL design**
**Steel skin thickness – scaled to 3.99 mm (LBL design 1.35 mm) to compensate for difference in thickness of coil package – FNAL single coil package, LBL two coil package**
**End support parts – scaled to FNAL cable width**
**Winding Assembly**
**Wider cable – FNAL cos(********) cable**
**Double layer design (no interlayer splice) – 13 turns**
**Modified pole piece **
**Horseshoe, end shoe scaled to FNAL cable width**
**Leads on the same side**
**Tooling **
**Reaction, impregnation tooling parts scaled to FNAL cable width (where appropriate)**

- A. Zlobin

- 2/24/98

## Design Overview – Mechanical Structure

**6061 – T6 Aluminum Shell**

**Yoke – 1010 Steel**

**Pressure Pad – 1018 Steel**

**Load key –1018 Steel**

**Skin – 1010 Steel**

**Pole piece – 1010 Steel**

-  **horseshoe – 304 steel**

**End supports  – 304 Steel**

- A. Zlobin

- 2/24/98

## Design Overview – Winding Assembly

**R = 17.3 mm **

**R = 18.6 mm **

**13 turns**

- A. Zlobin

- 2/24/98

## Design Overview – Tooling

**Reaction Fixture**

**Impregnation Fixture**

- A. Zlobin

- 2/24/98

## Magnetic Analysis

*All parts in purple represent iron – saturation effects included*

- A. Zlobin

- 2/24/98

## Magnetic Analysis 

-  Peak field = 10.7 T
-  Total coil separation force  850 kN
-  Peak field based on roxie = 11.2 T, coil separation force = 750 kN
-    (Vadim Kashikin)

- I = 28 kA

- A. Zlobin

- 2/24/98

## Mechanical  Analysis – Design Criteria and Specifications

** ****No coil separation allowed @ I****max**** = 28 kA (Reacted Nb****3****Sn cable in the transition region from the top layer to the bottom layer)**
**Coil remains under compression @ 4.2 K, I****max**** = 28 kA**
**Maximum shell stress during bladder operation < yield stress of 6061 T6 Aluminum = 250 MPa**
**Maximum coil stresses during assembly and cool-down < 150 MPa**
**Key/yoke interference = 0.5 mm**
**Bladder pressure required for inserting keys = 60 MPa**
**Minimum friction between yoke and skin to reduce shell stresses during bladder operation**
**Shell stresses monitored using strain gages**

- A. Zlobin

- 2/24/98

## Mechanical  Analysis – ANSYS Model and Material Properties

-  Surface-surface contact elements (μ = 0.15)
-  μ = 0 contact elements between shell and yoke

- A. Zlobin

- 2/24/98

## Mechanical  Analysis – Azimuthal Shell Stresses

- Bladder on @ 60 MPa

- Bladder off, keys on

- 4.2 K

- 4.2 K, 28 kA

- A. Zlobin

- 2/24/98

## Mechanical  Analysis – Azimuthal Shell Strains

- Bladder on @ 60 MPa

- Bladder off, keys on

- 4.2 K

- 4.2 K, 28 kA

- A. Zlobin

- 2/24/98

## Mechanical  Analysis – Radial (Sx) Coil Stresses

_***Mechanical  Analysis – Radial (S***__***x***__***) Coil Stresses***_

- Bladder on @ 60 MPa

- Bladder off, keys on

- 4.2 K

- 4.2 K, 28 kA

- A. Zlobin

- 2/24/98

## Mechanical  Analysis – Radial (Ux) Coil Displacements

- Bladder off, keys on

- 4.2 K

- 4.2 K, 28 kA

- A. Zlobin

- 2/24/98

## Fabrication – Procurement Status

| Description | Design Modifications/ Drawings Release | Procurement | Expected Final Delivery Date  | No. of sets |
| --- | --- | --- | --- | --- |
| coil winding assembly | completed | Parts in QC | Aug 15,2003 | 2  |
| mechanical structure | completed | Parts in QC | Aug 15,2003 | 2 |
| Tooling – Reaction/Impregnation | completed | Requisition initiated | Sept 15 ,2003 | 2 |

- A. Zlobin

- 2/24/98

## Fabrication – Schedule

- A. Zlobin

- 2/24/98

## Fabrication – Schedule

- A. Zlobin

- 2/24/98

## Summary

**Design changes have been kept to a minimum**
**Modifications are being validated using FEA**
**Fabrication process has to follow LBL procedures as closely as possible (including the subtle steps)**
**Strong collaboration between FNAL and LBL essential for successful execution of the first small racetrack model magnet **

- A. Zlobin

- 2/24/98